What is Column Designer?

Column Designer is a comprehensive web-based software package for the analysis and design of concrete, reinforced concrete, and composite concrete columns. It supports both direct design and advanced analysis-based workflows, allowing engineers to efficiently evaluate column behavior under axial force, bending, and slenderness effects.

The program provides ready-to-use templates for common project types, including Building Frame Column, Bridge Pier, and Shear Wall, as well as tools for Retrofit Assessment.

Analysis & Design Capabilities

Column Designer supports interactive analysis and design, allowing users to immediately see the impact of input changes on results.

Column design options include:

• Direct design for specified axial loads and moments

• Automatic calculation of magnified moments due to slenderness

• Support for sway and non-sway conditions

• Code-based sway/non-sway checks

Figure: Overall analysis and design process in Column Designer

Effective Length Factor Evaluation

Column Designer can automatically determine the Effective Length Factor (K) based on:

• Column framing conditions

• End restraints

• Code-specified criteria

This allows accurate consideration of global stability effects without manual estimation.

Automatic Reinforcement Design

An Auto Design Tool is available to:

• Select optimum reinforcement layouts

• Follow user-defined design rules

• Satisfy axial and moment demand efficiently

This significantly reduces trial-and-error during reinforcement selection.

Results & Output

Column Designer generates a wide range of analytical and design results, including:

• Capacity interaction surfaces

• P–M interaction curves

• M–M interaction curves

• Moment–curvature relationships

• Flexural stress contours

Reporting & Documentation

Column Designer can generate customizable design reports as part of the analysis and design process.

Reports can be:

• Automatically generated

• Customized with additional text

• Enhanced with user-selected graphics

Cross-Section Modeling & Reinforcement Tools

Parametric Shapes

Column Designer provides a rich library of predefined shapes, including:

• Solid sections

• Hollow sections

• Flanged sections

• Composite sections using Standard Steel Database Shapes

Shape Editing & Construction

Users can:

• Merge multiple shapes

• Edit dimensions

• Draw custom geometries

• Create complex cross-sections efficiently

Advanced tools are provided for:

• Aligning shapes

• Stacking shapes

• Precise placement

Reinforcement Modeling

Reinforcement can be placed anywhere within the cross-section using flexible placement options.

Supported rebar patterns:

• Point

• Line

• Rectangle

• Circle

Design and Analysis Capabilities

Column Designer provides comprehensive tools for column analysis and design, supporting both simple and advanced workflows.

Key capabilities include:

• Guided column design using the Quick Design Wizard

• Import of columns from ETABS, including materials, sections, loads, and framing

• Design of columns in accordance with user-specified design codes

• Definition of any number of load combinations for sway and non-sway conditions

• Application of loads using:

  • Detailed mode for slender columns

  • Simple mode for short columns

• Analysis and design considering slenderness effects

• Automatic determination of optimum reinforcement using user-defined parameters through the Auto Design feature

Slenderness Considerations

Column Designer provides robust tools to evaluate and design columns considering slenderness effects.

Features include:

• Definition of column framing or import from ETABS

• Code-specific checks for sway and non-sway conditions

• Automatic determination of the Effective Length Factor (K) based on:

  • Framing configuration

  • End conditions

• Integrated analysis and design accounting for slenderness effects

Cross-Section Generation

Column Designer offers powerful and flexible tools for defining and editing column cross-sections.

Section Definition and Editing

• Define and edit multiple column sections simultaneously

• Create rectangular and circular columns using simple tools

• Import sections from:

  • ETABS

  • Text files

  • DXF files

Parametric and Composite Sections

• Use predefined parametric shapes, including:

  • Solid sections

  • Hollow sections

  • Flanged sections

• Access a large library of Standard Steel Shapes

• Create complex sections by combining:

  • Basic concrete shapes

  • Basic steel shapes

  • Standard steel shapes

  • User-defined shapes

• Merge shapes of different geometries to form complex cross-sections

Reinforcement Modeling

• Add reinforcement of any size anywhere within the cross-section

• Use multiple reinforcement placement patterns

• Apply reinforcement sets

Material Properties

Column Designer allows realistic modeling of material behavior using built-in stress–strain relationships.

Features include:

• Nonlinear stress–strain curves for concrete

• Stress–strain models for steel reinforcement

• Accurate representation of material behavior for analysis and design

Results Generated

Column Designer generates detailed analytical and design results to support both evaluation and reporting.

Geometric and Stress Results

• Computation and reporting of:

  • Cross-sectional area

  • Moments of inertia

  • Shear area

  • Reinforcement area

• Plotting of flexural stress contours due to axial load and biaxial bending (P, Mx, My)

Capacity and Interaction Results

• Generation of capacity interaction surfaces

• Detailed P–M diagrams, including:

  • Axial load capacity

  • Major moment capacity

  • Forces in concrete and reinforcement

  • Strain distribution

  • Neutral axis depth

• Plotting of multiple P–M or M–M curves in a single graph by varying:

  • Concrete compressive strength (fc′)

  • Steel yield strength (fy)

  • Reinforcement sizes

Advanced Performance Evaluation

• Generation of moment–curvature curves for arbitrary column shapes

• Evaluation of column performance and ductility

• Display of the location and orientation of the neutral axis for specific loading conditions

• Computation of capacity ratios using different methods

• Verification of section adequacy for specified load combinations

• Design of columns in accordance with the selected design code

Miscellaneous Features

Additional features enhance usability and reporting efficiency:

• Modeling of composite cross-sections using multiple materials

• Support for US and SI unit systems

• Creation of customized reports with user-added text

• Display of a summary of critical information for all columns, including:

  • Governing load combination

  • Reinforcement configuration

  • Reinforcement ratio

  • Corresponding D/C ratio

• Generation of a one-page summary report for all columns in the Project File

Some important terms that require clear understanding to help make the program more useful are defined below.

Project File

A Project File is where newly defined or pre-created columns can be saved for later use.
Several columns can be added and managed within a single Project File.

Column

A Column is a complete structural member that includes:

• A cross-section

• Framing conditions

• Load combinations

Section

A Section is a combination or collection of shapes placed together to act as a single cross-section.

• Section properties are computed at the section level

• Analysis and design are performed for a section, not for individual shapes
  (unless the section contains only one shape)

Figure shows a section made up of two shapes.

Figure: Section made of two shapes.

Shape

A Shape is the basic geometric component used to create sections.

Key characteristics:

• Rebar can be added to individual shapes or anywhere within the section

• Predefined shapes from standard libraries can be used and modified parametrically

• Shapes can be combined to form complex sections

Tools available to create shapes include:

• Draw Menu → Concrete Shapes

• Draw Menu → Steel Shapes

• Draw Menu → Add Shapes → Shape Library

• Draw Menu → Add Shapes → Steel Shapes

• Draw Menu → Add Shapes → Coordinates

Shapes can also be imported from:

• .txt files

• .DXF files

• .csv files

using the tools under Draw Menu → Import Shapes.

Notes on importing rebars

• Format for importing rebars:
  (x-coordinate, y-coordinate, rebar diameter)

• If the imported file contains rebar diameters larger than those defined in the Project:

  • The user must add the new diameters to Rebar Sets under
    Options → General → Rebar Sets before importing

  • Otherwise, the program will automatically assign the maximum available diameter from the Rebar Sets

Shape Library

The Shape Library is a collection of standard predefined shapes that can be:

• Edited parametrically (by specifying dimensions), or

• Imported from standard databases

The software includes several built-in shape libraries.

Modes

Column Designer operates in three different modes:

1. Selection Mode

Selection Mode is activated when Edit Menu → Select is clicked.

In Selection Mode:

• Shapes can be selected but not edited directly using the mouse

• Shapes can be edited using the Property Grid

• Shapes can be aligned using:

  • Edit Menu → Align

• Shapes can be moved using:

  • Edit Menu → Edit → Move Sections

2. Drawing Mode

Drawing Mode is activated when drawing options are selected from:

• Home Menu → Draw → Rebars

• Home Menu → Draw → Shapes

• Draw Menu → Rebars

• Draw Menu → Concrete Shapes

• Draw Menu → Steel Shapes

In Drawing Mode:

• The cursor changes to a “+” symbol

• Multiple objects can be drawn consecutively

• Drawing Mode can be exited by pressing the Esc key

3. Results Mode

Results Mode is activated when column results are viewed from:

• Results Menu, or

• Project Explorer → Columns → Results

In Results Mode:

• No changes to the section are allowed

• Tools under the Edit Menu and Draw Menu are disabled

To exit Results Mode and modify the section:

• Select the desired section from Project Explorer → Columns

Axis

Various editing operations, computed properties, and shape locations are referenced to the global X and Y axes.

Two coordinate systems are used in Column Designer:

1. X–Y Axis System

   • A global, fixed reference on the screen

   • Used to locate shapes relative to a common origin

2. 2–3 Axis System

   • Indicates the location of the section’s centroid

   • The origin changes as the shape size or location changes

   • Provided for compatibility with the member local axis system used in CSI programs such as SAP2000 and ETABS

In CSI programs:

• The 1–1 axis passes through the member’s longitudinal axis

Figure illustrates a section showing the local axes.

Figure: Section in 3D showing local axes.

Column Designer generates the following types of results:

• Section Properties

• Stress Distribution

• Magnified Moments

• Section Capacity

• Moment–Curvature

• Multiple Curves

Section Properties

Column Designer reports the following properties for the selected section:

Basic Properties

• Cross-sectional area

• Shear areas

• Moments of inertia

• Torsional constant

Section Bounds

• Overall section dimensions

• Centroid location with respect to:

  • Global origin

  • Local origin

Additional Properties

• Radii of gyration

• Section moduli

Rebar Properties

• Total reinforcement area

• Reinforcement ratio of the selected section

Note:
For composite sections, concrete is considered as the base material, and the transformed section properties are reported.

Stress Distribution

Column Designer can display flexural stress distribution on the section for a selected load combination and section location.

Key features include:

• Stress displayed as color-coded contours

• Visualization available in:

  • 2D view

  • 3D view

• Stress contours shown directly in the working area

Magnified Moments

Column Designer performs detailed slenderness calculations to determine magnified design moments for both sway and non-sway loading conditions, in accordance with the selected design code.

The final design loads can be viewed from:

• Results Menu → Capacity → Design Loads, or

• Project Explorer → Columns → Results → Design Loads

The Design Loads form allows the user to:

• Select loading direction:

  • Along X

  • Along Y

• View magnified moments corresponding to:

  • M_ux (moment about the X-axis)

  • M_uy (moment about the Y-axis)

Magnified moments are calculated based on the selected design code.
Currently supported design codes include:

• ACI 318-19

• ACI 318-14

• ACI 318-11

• ACI 530-11

• AASHTO LRFD 2020

• AS 3600-18

• BS 8110-97

• Chinese 2010

• CSA A23-3-14

• Eurocode 2:2004

• Hong Kong CP: 2013

• IS 456: 2000

• Italian NTC 2008

• KBC 2016

• Mexican RCDF: 2017

• NZS 3101: 2006

• Singapore CP 65-99

• TS 500: 2000

Section Capacity

Section capacity can be obtained using the following approaches.

P–M Interaction Curves

Capacity interaction curves are displayed in the following forms:

Interaction Surface

• A 3D color-coded plot showing the variation of:

  • Axial load (P)

  • Moment about local 2-axis (M₂)

  • Moment about local 3-axis (M₃)

P–M Curve

• Load–moment interaction curves showing the relationship between:

  • Axial load capacity

  • Resultant moment capacity

• Curves are generated for a specified neutral axis angle

M–M Curve

• Moment–moment interaction curves showing the relationship between:

  • Moment capacity about the local 2-axis

  • Moment capacity about the local 3-axis

• Generated for a specified axial load level

Note:
Although Column Designer can generate capacity curves for any section and combination of shapes and materials, users should ensure that the results are valid and applicable for the intended design scenario.

Capacity Ratio Check

Column Designer can calculate and report capacity ratios for column sections using the following methods:

• Moment Sum at P

• Moment Vector at P

• Axial Capacity Ratio

In addition, the program reports:

• Resultant moment

• Resultant moment angle

• Neutral axis angle

• Neutral axis depth

The section adequacy is determined based on the maximum capacity ratio obtained from the different methods:

• Capacity ratio ≤ 1.0 → Section is adequate

• Capacity ratio > 1.0 → Section is inadequate

Note:
The neutral axis depth is calculated for the nominal moment corresponding to the factored axial force on the relevant P–M interaction curve for the selected moment direction.

Moment–Curvature

Moment–curvature curves can be generated:

• For any orientation of the neutral axis

• For a specified level of axial load

These curves are useful for evaluating section performance and ductility.

Multiple Curves

Column Designer allows multiple P–M or M–M diagrams to be plotted on the same graph by varying:

• Concrete compressive strength (f_c′)

• Steel tensile strength (f_y)

• Reinforcement sizes

This feature enables comparative studies of material properties and reinforcement configurations.

The Column Auto Design feature is a highly effective and efficient tool for designing reinforcement for both sway and non-sway columns, with or without consideration of slenderness effects.

The Auto Design tool designs the column section based on user-defined design parameters, including:

• Selected design codes

• User-specified design criteria

The program automatically optimizes the column design to satisfy a user-defined maximum capacity ratio limit.

Design constraints that can be specified by the user include:

• Maximum rebar size

• Minimum rebar size

• Maximum allowable rebar ratio in the section

By applying these constraints, Column Designer identifies an optimum reinforcement layout that meets both strength and code requirements while maintaining design efficiency.

This feature is explained in further detail in Designing Column.

Upon launching Column Designer, users are presented with a clean, browser-based home screen organized into the following areas:

Quick Design Wizard A highlighted panel at the top, a step-by-step guided workflow that walks users through the column design process from start to finish. This is the recommended starting point for new users.

Templates Four project templates are available for common design scenarios:

• Building Frame Column: Design reinforced concrete building columns

• Bridge Pier: Design of bridge substructure piers

• Shear Wall: Core sections under combined axial load and bending

• Retrofit Assessment: Evaluate and strengthen existing structures

New Column

• From ETABS: Import an ETABS EDM file directly

• Rectangular: Generate a rectangular column model

• Circular: Generate a circular column model

• Blank: Start from scratch with a blank model

Navigation Panel The left sidebar provides access to project-level actions, including importing an existing project and installing the ETABS Extractor for data exchange.

Column Designer provides ready-to-use templates to streamline project setup. Each template pre-configures the relevant parameters for a specific column type, helping users get started quickly.

To use a template, select it from the home screen. A configuration dialog will open where parameters can be reviewed and adjusted before the project is created.

The Building Frame Column template is intended for standard reinforced concrete columns in building structures subjected to gravity and lateral loads.

The configuration dialog is organized into the following sections:

General Setup Set the basic project parameters:

• Unit System: Choose between US Customary and SI units

• Design Code: Select the applicable design standard (e.g., ACI 318-19)

• Column Type: Specify whether the column is a Short Column or a slender column

Materials Define the concrete and reinforcement material properties.

Section Geometry Specify the cross-sectional dimensions of the column.

Reinforcement Configure the rebar layout, including concrete cover, bar size and arrangement.

A live preview of the column cross-section is displayed on the right side of the dialog, updating as parameters are adjusted. A Configuration Summary at the bottom provides a quick overview of the key settings, including column type, design code, concrete strength, and rebar yield strength.

Once all parameters are set, click Create Project to open the column in Column Designer.

The Bridge Pier template is configured for design of bridge substructure piers, using AASHTO LRFD as the default design code.

The configuration sections (General Setup, Materials, Section Geometry, and Reinforcement) follow the same structure as the Building Frame Column template.

Slenderness Effects When the column type is set to Long Column, an additional Slenderness Effects section becomes available across all templates. It allows users to define effective length factors for both the XZ and YZ planes, with separate values for braced and unbraced conditions, as well as column height and center-to-center length parameters.

The Shear Wall template is configured for core sections under combined axial load and bending. The General Setup, Materials, and Reinforcement sections follow the same structure as the other templates.

The Retrofit Assessment template is designed for evaluating and strengthening existing column structures.

This template includes one additional section:

Retrofit Options Users can select one or both of the following strengthening methods:

• Add Concrete Jacketing: Adds a concrete jacket layer around the existing section

• Add Steel Jacketing: Adds a steel jacket around the existing section

The cross-section preview updates to reflect the selected jacketing configuration, showing both the original and the enlarged retrofitted section dimensions.

The New Column section provides four options for starting a column model directly, without using a predefined template. Clicking any option opens the selected column type directly in the Column Designer interface.

• From ETABS: Imports an existing column from an ETABS EDM file, carrying over the section and load data defined in the structural model

• Rectangular: Opens a new rectangular column model ready for configuration

• Circular: Opens a new circular column model ready for configuration

• Blank: Opens an empty model with no predefined geometry, suitable for custom or non-standard column configurations

Column Designer’s user interface is designed to be user-friendly and intuitive. The interface consists of a drawing area along with various menus and panels that allow efficient modeling, analysis, and design.

The components of the interface are described in the sections below.

Figure: Column Designer Working Window

The Column Designer graphical user interface includes the following main components:

• Ribbon Menu Bar

• Working Area

• Project Explorer

• Context-Sensitive Area

Each component is described below.

Ribbon Menu Bar

The Ribbon Menu Bar contains the program menus from which various actions can be performed.

Common menus include:

• File

• Home

• Edit

• Define

• Draw

• Results

• Cloud

• Options

• Help

Each menu provides access to relevant commands and tools.

Figure: Column Designer Ribbon Menu Bar

Working Area

All creation and modification of shapes and sections take place in the Working Area.

Key characteristics:

• Automatically updates as shapes are added, moved, resized, rotated, or combined

• Supports creation of sections with arbitrary geometry and size

• Displays a graph-paper style grid to assist with:

  • Placement

  • Alignment

  • Resizing of shapes and sections

Project Explorer

The Project Explorer provides structured access to project data and includes four main views:

• Materials
  Used to view and modify material properties defined in the Project File.

• Stress-Strain
  Used to view and edit stress–strain curves for materials.

• Columns
  Allows access to:

  • Shapes

  • Rebar patterns

  • Framing conditions

  • Loadings

Results for each column can also be accessed from this view.

• Report
  Used to generate:

  • Column Summary

  • One-page Simple reports

  • Detailed reports for the selected column

Materials and stress–strain definitions can be reused across multiple columns in the Project File.

Figure: Column Designer Project Explorer

Context-Sensitive Area

The Context-Sensitive Area displays grids and panels that change based on user actions.

Examples:

• The Property Grid becomes active when a shape or rebar is selected.

• Different grids appear depending on:

  • The selected tool

  • The selected object

This area allows editing without opening additional dialog boxes.

Figure: Column Designer Context-Sensitive Area

Column Designer provides several settings under the Options Menu that allow customization of parameters used globally within the current Project File.

These parameters include:

• Working units

• Design code

• Number formatting

• View options

• Diagram display settings

General Options control parameters that affect all sections globally in the current Project File.

Units Drop-Down List

The Units drop-down list defines the working units for the model.
The selected units apply globally to all sections in the Project File.

Figure: Units Drop-Down List

Currently supported unit systems:

• US Customary

• Metric SI

US Customary Units

Metric SI Units

Code Drop-Down List

The Code drop-down list allows selection of the design code used by Column Designer.

The selected code is used to determine:

• Capacity reduction factors

• Axial compression limits

• Maximum allowable concrete strain

• Material reduction factors

Note:
Changing the design code will erase all previously generated results.
The user will be prompted to confirm before the design code is updated.

Figure: Code Drop-Down List

Rebar Sets Button

The Rebar Sets button opens the Add Rebar Sets form, allowing the user to:

• Add new rebar sizes

• Remove existing rebar sizes

Rebars may be added by:

• Manually entering bar name and diameter, or

• Importing from standard libraries (e.g., ASTM)

Figure: Rebar Sets Button in Options Menu

Interface Theme

Column Designer supports both light and dark display themes. Users can switch between them by selecting the desired option from the Theme dropdown, located in the General group under the Options menu.

Number formatting settings are available under Options Menu → Number Format.

Decimals Drop-Down List

Controls the number of decimal places displayed for numeric values.

Figure: Decimals Drop-Down List in Options Menu

Separator Drop-Down List

Controls the separators used for thousands and decimal values.

Figure: Separator Drop-Down List in Options Menu

Show Exponent Button

Displays numeric values in exponential notation when enabled.

Figure: Show Exponent Button in Options Menu

View options are available under Options Menu → View and control visibility of working-area elements.

Available toggles:

• Grid – Show or hide the working grid

• Ruler – Show or hide the ruler

• Dimensions – Show or hide shape and rebar dimensions

• Global Axis – Show or hide global X and Y axes

• Local Axis – Show or hide local 2 and 3 axes

Figure: View Options in Options Menu

Diagram display settings are available under Options Menu → Diagrams.

Available options:

• Points – Show or hide data points

Figure: Diagram Points Option in Options Menu

• Labels – Show or hide data point labels

Figure: Data Points Label Option in Options Menu

• Curves Drop-Down List – Specify the number of curves for interaction diagrams

Figure: Curves Drop-Down List in Options Menu

• Points Drop-Down List – Specify the number of points displayed on diagrams

Figure: Points Drop-Down List in Options Menu

Strength reduction factors (or Partial Safety Factors, depending on the selected design code) can be modified under:

• Options Menu → Strength Reduction Factors

These factors are used to generate P–M interaction curves.

Note:
By default, these values are set according to the selected design code.

This section describes how to use Column Designer to efficiently create column sections and compute their capacities. It also explains the overall column design process implemented in the program.

It is strongly recommended that users read this section before using Column Designer. This section assumes that the user is familiar with:

• Basic concepts of structural mechanics

• Structural analysis

• Fundamental principles of column design

In column design, the engineer must determine the following parameters:

• Appropriate cross-sectional dimensions

• Cross-section shape

• Material properties

• Amount and distribution of reinforcement

These parameters are selected based on:

• Applied actions (axial loads and moments)

• Column geometry

• Framing and boundary conditions

Column Designer provides a set of convenient and powerful tools to assist engineers in determining the most effective and efficient design parameters for a given set of applied actions.

These tools include:

• Quick Design Wizard

• Templates

• Shape Libraries

• Rebar Patterns

• Auto Design feature

Tools related to editing shapes within a section are described in Editing Column Cross sections.

Column Designer provides several methods for creating column sections. Columns can be created using any of the following approaches.

Quick Design Wizard

File Menu → Quick Design Wizard

This option launches the Quick Design Wizard, which provides access to all the forms required to complete the entire column modeling, analysis, and design process.

Using the Quick Design Wizard, users can:

• Define column geometry and cross-section

• Specify framing conditions

• Apply loads

• Generate analysis results

• Create design reports

This method represents the default and recommended process for creating rectangular or circular columns.

Blank Model

File Menu → Blank Model

This option opens a blank working area that can be used to create a column of any shape.

With this method:

• Shapes must be added using the tools available under the Draw Menu

• Shapes are modified using the tools available under the Edit Menu

• Column framing and loading must be defined independently using the Define Menu

• Analysis results are generated using the Results Menu

• Reports can be viewed from:

  • Results Menu → Reports, or

  • Project Explorer → Report

This method provides maximum flexibility for creating custom and complex sections.

Rectangular Model

File Menu → Rectangular Model

This option creates a predefined rectangular column section.

After creating the rectangular section:

• Column framing and loading must be defined using the Define Menu

• Analysis results are generated using the Results Menu

• Reports can be viewed from:

  • Results Menu → Reports, or

  • Project Explorer → Report

Circular Model

File Menu → Circular Model

This option creates a predefined circular column section.

After creating the circular section:

• Column framing and loading must be defined using the Define Menu

• Analysis results are generated using the Results Menu

• Reports can be viewed from:

  • Results Menu → Reports, or

  • Project Explorer → Report

Editing Column Sections

After a column section has been created using any of the methods described above, the shapes comprising the section can be edited using the tools described in Editing Column Cross section.

These tools allow the user to:

• Add or delete shapes

• Modify shape geometry

• Add, change, or distribute reinforcement

The Quick Design Wizard appears when Column Designer is started.

The general process for using the Quick Design Wizard is described below.

Using the Quick Design Wizard

1. Access the Quick Design Wizard
   Click Quick Design Wizard to open the Quick Design Wizard form.

Figure: Quick Design Wizard Form

2. Project Details
   Click the Define button next to Project Details to open the Project Information form.

Figure: Project Details Option in Quick Design Wizard Form

Enter project-related information such as:

• Project Name

• Project Code

• Engineer

• Company

The Project Information form can also be accessed later from:
Define Menu → Project → Project Details

Figure: Project Details Option in Define Menu

The information entered here appears at the beginning of the detailed reports generated for the Project File.

3. Units and Code
   Click the Define button next to Units and Code to open the Options form.

Figure: Units and Code Option in Quick Design Wizard Form

Review and accept the default values or modify parameters such as:

• Working units

• Design code

• Number format

These settings can also be modified later using the drop-down lists under the Options Menu.

Figure: Units and Code Option in Options Menu

4. Material Properties
   Click the Define button next to Material Properties to access the Material Properties form.

Figure: Material Properties Option in Quick Design Wizard Form

This form contains separate tabs for:

• Concrete materials

• Rebar materials

Review the default values or enter the desired material properties.

The Material Properties form can also be accessed later from:

• Define Menu → Project → Materials, or

• The button next to Project Explorer → Materials

Figure: Material Properties Option in Define Menu and Project Explorer

5. Column Name
   The column name can be defined or modified from:

   • Define Menu → Project → Columns, or

   • The button next to Project Explorer → Columns

6. Section Shape
   Select the stirrup type (Tied or Spiral) and section shape type (Rectangular or Circular) to open the corresponding form.

Figure: Section Shape Option in Quick Design Wizard Form

Define:

• Shape name

• Cross-section dimensions

• Clear cover

• Rebar size

• Rebar distribution

Shapes and reinforcement can be modified later by selecting them and editing their properties in the Property Grid.

7. Consider Slenderness Toggle

   • When this toggle is turned on, Column Designer considers slenderness effects and column framing must be defined using the Define Framing button.

   • When this toggle is turned off, slenderness effects are ignored, the Define Framing button is disabled, and the user may proceed directly to Step 9.

Figure: Slenderness Option in Quick Design Wizard Form

8. Define Framing
   This option is available only when slenderness effects are considered.
   Clicking Define Framing opens the Column Framing Conditions form.

Figure: Framing Option in Quick Design Wizard Form

This form can also be accessed later from:

• Define Menu → Slenderness → Framing Conditions, or

• The button next to Project Explorer → Columns → Framing → Conditions

Figure: Slenderness Option in Define Menu and Project Explorer

9. Define Loading
   Either Detailed Loading or Simple Loading can be defined.

   • If the Consider Slenderness toggle is on, the Detailed Loading form is displayed automatically.

   • If the toggle is off, the Simple Loading form is displayed automatically.

Figure: Load Definition in Quick Design Wizard Form

The loading definition form can also be accessed later from:

• Define Menu → Loading → Loading, or

• The button next to Project Explorer → Columns → Loading

Figure: Load Definition in Define Menu and Project Explorer

10. Results
    Once the column section, loading, and framing conditions have been defined, results can be viewed using the options available under the Results section of the wizard.

Available result options include:

• Capacity Ratio – Determines whether the column section is adequate for the defined loading

• Detailed Results – Displays detailed analysis and design results

• Interaction Diagrams – Displays PMM interaction diagrams

• Generate Report – Creates a one-page report for the defined column

Figure: Result View in Quick Design Wizard Form

After closing the wizard:

• All results can be accessed from the Results Menu or Project Explorer → Results

• Reports can be viewed from Project Explorer → Report

Figure: Result View and Report Generation in Results Menu and Project Explorer

When the Blank Model button is used, Column Designer adds a blank working area to the current Project File.
This method provides maximum flexibility and allows the user to create a column section of any shape.

Figure: Blank Model Option in Column Designer

The basic procedure for creating a section using File Menu → Blank Model is described below.

Procedure for Creating a Column Using Blank Model

1. Create a Blank Model
   Select Blank Model to add a blank working area to the current Project File.

Figure: Blank Working Area in Column Designer

2. Set Units and Design Code
   By default, Column Designer opens using the last selected working units and design code.
   If required, modify these settings using:

   • Options Menu → General

Figure: Setting Units and Design Code in Column Designer

3. Define Concrete Stress–Strain Model
   Use:

   • Define Menu → Stress Strain → Concrete, or

   • The button next to Project Explorer → Stress-Strain → Concrete

to access the Define Concrete Confinements form and define or modify concrete confinement models.

Figure: Defining Concrete Stress-Strain Model in Column Designer

4. Define Steel Stress–Strain Model
   Use:

   • Define Menu → Stress Strain → Steel, or

   • The button next to Project Explorer → Stress-Strain → Steel

to access the Define Steel Stress–Strain form and define or modify steel stress–strain models.

Figure: Defining Steel Stress-Strain Model in Column Designer

5. Define Material Properties
   Use:

   • Define Menu → Project → Materials, or

   • The button next to Project Explorer → Materials

to access the Material Properties form and define concrete and reinforcement properties.

Figure: Defining Material Properties in Column Designer

6. Add Shapes to the Section
   Use one or more of the following tools to add shapes to the current column section:

a. Draw Menu → Concrete Shapes
Draw basic concrete shapes directly in the working area.

Figure: Drawing Concrete Shapes in Column Designer

b. Draw Menu → Steel Shapes
Draw basic steel shapes directly in the working area.

Figure: Drawing Steel Shapes in Column Designer

c. Draw Menu → Add Shapes → Shape Library
Select shapes from the predefined shape libraries.

Figure: Shape Library in Column Designer

d. Draw Menu → Add Shapes → Steel Shapes
Access libraries of standard steel shapes.

Figure: Drawing Standard Steel Shapes in Column Designer

e. Draw Menu → Add Shapes → Coordinates
Open the Add Points form to:

• Enter coordinates manually, or

• Import coordinates from external sources.

Figure: Adding Shapes by Coordinate Points in Column Designer

f. Draw Menu → Import Shapes → Text File
Import shapes from coordinates stored in a text file.

g. Draw Menu → Import Shapes → DXF File
Import shapes from a DXF file.

Figure: Import Shapes Options in Column Designer

7. Add Additional Shapes
   Repeat Step 6 to add multiple shapes to form the desired column cross-section.

8. Edit and Modify Shapes
   Use tools available under the Edit Menu, such as:

   • Flip

   • Merge

   • Stack

   • Align

   • Edit

to modify the shapes and obtain the required section geometry.

Figure: Editing/Modify Options in Column Designer

9. Add Reinforcement
   Use the tools under Draw Menu → Rebars to add reinforcement to the section.
   Reinforcement can be added as:

   • Points

   • Lines

   • Rectangular patterns

   • Circular patterns

Figure: Adding Rebars Options in Column Designer

10. Edit Shape and Rebar Properties
    Click on a shape or rebar to activate the Property Grid and edit dimensions and other properties numerically.

    • The Property Grid for concrete and steel shapes includes a Stress–Strain tab

    • Assigned stress–strain models can be viewed and modified if required

    • The Property Grid can also be accessed by selecting shapes or rebars from the Project Explorer → Columns view

Note:

• Shapes created using Draw Menu → Concrete Shapes → Polygon can only be edited by modifying nodal coordinates:

  • From the Points tab of the Property Grid, or

  • Using Edit Menu → Edit → Edit Points

• Parametric shapes can be converted to polygons using Edit Menu → Edit → Edit Points

Figure: Editing Shapes and Rebar Properties in Column Designer

11. Enable Slenderness Effects (if applicable)
    If the column is slender, click:

    • Define Menu → Slenderness → Slenderness Effects

If the column is not slender, skip this step and Step 12.

12. Define Framing Conditions (for Slender Columns)
    For slender columns, define framing conditions using:

    • Define Menu → Slenderness → Framing Condition, or

    • The button next to Project Explorer → Columns → Framing → Conditions

Note:
This option is available only when slenderness effects are enabled.

Figure: Framing Conditions for Slender Column in Column Designer

13. Define Loading
    Define column loads using:

    • Define Menu → Loading → Loading, or

    • The button next to Project Explorer → Columns → Loading

Figure: Load Definition in Column Designer

14. Apply Auto Design
    Use Home Menu → Design → Auto-Design to perform an iterative design process that determines:

    • Minimum required reinforcement

    • Reinforcement layout for the governing load combination

The design satisfies user-defined limits for:

• Minimum and maximum bar sizes

• Clear cover

• Clear spacing

• Maximum rebar ratio

• Maximum D/C ratio

Note:
Auto Design is available only for rectangular and circular reinforced sections.

Figure: Auto Design Feature in Column Designer

15. Review Results
    Use the options under:

    • Results Menu, or

    • Project Explorer → Columns → Results

to review analysis and design outputs for the column section.

Figure: Viewing Result Options in Column Designer

16. Generate Reports
    Use the Report view of the Project Explorer to:

    • View the column summary

    • Generate a one-page report

    • Generate a detailed report

for the selected column.

Figure: Various Reports Generated in Column Designer

Use the Rectangular Model or Circular Model button to add a new rectangular or circular column section to the current Project File.
This method provides a quick way to create a standard column section, after which framing, loading, analysis, and design can be completed.

The basic procedure for creating a rectangular or circular column is described below.

Procedure for Creating a Rectangular or Circular Column

1. Create a Column Model

Select one of the following from the File Menu to add a column section to the current Project File:

• Rectangular Model, or

• Circular Model

Figure: Creating a Rectangular or Circular Column using Template

2. Set Units and Design Code

By default, Column Designer opens using the last selected working units and design code.

If required, modify these settings using:
o Options Menu → General

Figure: Setting Units and design Code in for Circular/Rectangular Columns

3. Define Concrete Stress–Strain Model

Use:
o Define Menu → Stress Strain → Concrete, or
o The button next to Project Explorer → Stress-Strain → Concrete

to access the Define Concrete Confinements form and define new confinement models or modify the default one.

Figure: Defining Concrete Stress-Strain Model for Circular/Rectangular Columns

4. Define Steel Stress–Strain Model

Use:
o Define Menu → Stress Strain → Steel, or
o The button next to Project Explorer → Stress-Strain → Steel

to access the Define Steel Stress–Strain form and define new steel stress–strain models or modify the default one.

Figure: Defining Steel Stress-Strain Model for Circular/Rectangular Columns

5. Define Material Properties

Use:
o Define Menu → Project → Materials, or
o The button next to Project Explorer → Materials

to access the Material Properties form and define:
o Concrete properties
o Rebar properties
o Steel properties

Figure: Defining Material Properties for Circular/Rectangular Columns

6. Edit Shape and Rebar Properties (if required)

Click on the column shape or reinforcement to activate the Property Grid and edit dimensions or other properties numerically.

o The Property Grid for concrete and steel shapes includes a Stress–Strain tab
o Assigned stress–strain models can be viewed and modified if necessary
o The Property Grid can also be accessed by selecting the shape or rebar from Project Explorer → Columns view

Figure: Editing Shape/Rebars General Options for Circular/Rectangular Columns

Figure: Editing Stress-Strain Model and Materials Properties for Circular/Rectangular Columns

7. Enable Slenderness Effects (if applicable)

If the column is slender, click:
o Define Menu → Slenderness → Slenderness Effects

If the column is not slender, skip this step and Step 8.

Figure: Enabling Slenderness Effect

8. Define Framing Conditions (for Slender Columns)

If slenderness effects are enabled, define the framing scenario using:
o Define Menu → Slenderness → Framing Condition, or
o The button next to Project Explorer → Columns → Framing → Conditions

Note:
This option is available only when slenderness effects are being considered.

Figure: Framing Conditions for Slender Columns in Column Designer.

Figure: Effective Length Factors and Column Lengths in Column Designer.

9. Define Loading

Define the column loading using:
o Define Menu → Loading → Loading, or
o The button next to Project Explorer → Columns → Loading

Figure: Load Definition in Column Designer.

10. Apply Auto Design

Use Home Menu → Design → Auto-Design to perform an iterative design process that determines:
o Minimum required reinforcement
o Reinforcement layout for the governing load combination

The design satisfies user-defined limits for:
o Minimum and maximum bar sizes
o Clear cover
o Clear spacing
o Maximum rebar ratio
o Maximum D/C ratio

Note:
Auto Design is available only for rectangular and circular reinforced sections.

Figure: Auto Design Feature in Column Designer.

11. Review Results

Use the options available under:
o Results Menu, or
o Project Explorer → Columns → Results

to review analysis and design outputs for the selected column.

Figure: Effective Length Factors and Column Lengths in Column Designer.

12. Generate Reports

Use the Report view of the Project Explorer to:
o View the column summary
o Generate a one-page report
o Generate a detailed report

for the selected column.

Figure: Reports Feature in Column Designer.

Columns can be imported into Column Designer from the ETABS:

The Import ETABS Model button allows the user to select an existing ETABS model and import the concrete columns defined in that model into Column Designer.

The basic procedure for importing an ETABS model is described below.

Procedure for Importing Columns from ETABS

1. Select ETABS Model File
   Click the Import ETABS Model button to open the Open ETABS Model form.
   Browse to the desired ETABS model file, select it, and click Open.

2. Select Stories and Load Combinations
   Select the stories and load cases or load combinations to be imported into Column Designer.

Figure: Select Load Cases/Combinations to Import

3. Select Columns from ETABS Model
   After selecting the stories and load combinations, the ETABS Model form is displayed.
   This form allows the user to:

   • View the 3D ETABS model

   • Visually select the columns to be imported

   • Select multiple columns simultaneously

   • View properties of selected columns in the Property Grid

Columns can also be selected based on section type and story location by clicking the button in the context-sensitive toolbar.

Figure: Importing Columns from ETABS Model

Notes on Importing from ETABS

• This feature works only if ETABS is installed on the computer.

• If the file path to the ETABS executable has not been set previously, the user will be prompted to define it.

• Imported columns include:

  • Loading conditions

  • Material assignments

  • Framing conditions

• Effective Length Factors (K) are not imported.

• By default, the working units in Column Designer will match the database units used in ETABS.

• Currently supported unit systems in Column Designer:

  • US (inch)

  • SI (mm)

• If the ETABS model uses the MKS system, it is automatically converted to SI (mm).

• If the ETABS model uses an older version of a design code available in Column Designer, the model opens using the newer version of that design code.

• If the design code used in ETABS is not available in Column Designer, the model opens using the default design code (ACI 318-19).

If the ETABS building model has not been analyzed and designed, only the model geometry is imported.
If a column is failing in ETABS, it can still be imported, but reinforcement details will not be available.

Viewing Imported ETABS Columns

• Imported columns are listed under Project Explorer → Columns.

• When more than 10 columns are imported, only 10 columns are shown at a time.

• To view all imported columns in tabular form:

  • Click the button next to Project Explorer → Columns, or

  • Use Define Menu → Project → Columns

Important Note on Clear Cover

Unlike ETABS, the clear cover in Column Designer is measured up to the outer edge of the main bar.

Therefore, when importing sections from ETABS:

• The tie diameter is added to the clear cover of the confinement bars

• This adjusted value is used as the clear cover in Column Designer

Regardless of the method used to create a column, shapes from the standard shape libraries can be added to a column section. This allows the creation of complex and composite column sections.

Tools for merging and editing shapes are described in Editing Column Cross sections.

Shapes can be added from the following libraries:

• Basic Concrete Shapes

• Basic Steel Shapes

• Shape Library

• Steel Shapes

Each option is described below.

Select any of the basic concrete shapes available under:

Draw Menu → Concrete Shapes

These tools allow shapes to be drawn directly in the working area.

Available basic concrete shapes include:

• Rectangle

• Box

• Circle

• Tee

• Pipe

• Channel

• Angle

Shapes of arbitrary geometry can also be created graphically by selecting the Polygon shape and drawing it directly in the working area.

Figure: Adding Basic Concrete Shapes in Draw Menu

Select any of the basic steel shapes available under:

Draw Menu → Steel Shapes

These tools allow steel shapes to be drawn directly in the working area.

Available basic steel shapes include:

• Tube

• Pipe

• Angle

• Tee

• Channel

Figure: Adding Basic Steel Shapes in Draw Menu

Click:

Draw Menu → Add Shapes → Shape Library

to access a selection list of predefined shapes.

The Shape Library includes shapes from various standard and specialized libraries, such as:

• AISC Steel Shapes

• BS Steel Shapes

• CISC Steel Shapes

• Basic Concrete and Steel Shapes

• Box Girder Shapes

• Bridge Pier Shapes

• Cold-Formed Shapes

• Fillet and Chamfer Shapes

• Plate Library

• Rounded Steel Shapes

• Shear Walls

These shapes can be edited parametrically after insertion.

Figure: Adding Shapes from Shape Library in Draw Menu

Select standard steel shapes by clicking:

Draw Menu → Add Shapes → Steel Shapes

This option provides access to a library of predefined standard steel sections, which can be added directly to the column section.

Figure: Adding Standard Steel Shapes in Draw Menu

A shape can be defined by explicitly specifying its nodal point coordinates.
Coordinates may be entered manually using the keyboard or imported from an external file.

Supported external sources include:

• Comma-separated text files

• Tab-separated text files

• Space-separated text files

Defining a Shape Using Coordinates

The following options are available for defining shapes by coordinates:

• Draw Menu → Add Shapes → Coordinates
  Click this option to open the Add Points form.
  In this form, coordinate values for the desired shape can be:

  • Entered directly using the keyboard, or

  • Imported from an external file using the Import button

• Draw Menu → Import Shapes → Text File
  Click this option to import a shape directly from a text file containing the nodal coordinates.

These methods are useful for creating irregular or user-defined geometries that cannot be easily drawn using parametric shape tools.

Figure: Adding Shapes using Coordinates in Draw Menu

Column Designer allows users to import custom shapes from DXF files created in AutoCAD.

To import a shape:

• Use Draw Menu → Import Shapes → DXF File

• Select the DXF file containing the shape

Note:
This feature is intended only for importing shapes.
Rebar layouts cannot be imported using a DXF file.

Column Designer allows users to export shapes for use in external drafting and CAD applications.

To export a shape:

• Use Draw Menu → Export → Export Section as DXF File

• Select the desired shape or section

• Save the file in DXF format

The exported DXF file can be opened and edited using AutoCAD or other compatible CAD software.

Figure: Exporting Shapes Option in Draw Menu

Reinforcement bars can be added to a column section using different patterns as required.
Rebar placement tools are available under Draw Menu → Rebars.

The available rebar drawing options are described below.

Rebar Drawing Options

• Point
  Use this option to draw a single rebar by clicking at the desired location in the working area.

Figure: Single Rebar Drawing Using Point Option in Draw Menu

• Line
  Use this option to draw a line of rebars along a specified direction.

Figure: Drawing Multiple Rebars Using Line Option in Draw Menu

• Rectangle
  Use this option to draw rebars arranged in a rectangular pattern.

• Circle
  Use this option to draw rebars arranged in a circular pattern.

Figure: Drawing Rectangular/Circular Rebar Pattern Option in Draw Menu

Import Rebars

Rebars can also be imported from an external file by clicking:

Draw Menu → Import Shapes → Rebar

This option allows reinforcement to be imported from a CSV file.

Figure: Import Rebar Option in Draw Menu

Important Notes on Rebars

• The following parameters can be modified using the Property Grid:

  • Number of rebars in a pattern

  • Clear cover

  • Minimum clear spacing

The Property Grid is activated by:

• Clicking on a rebar in the working area, or

• Selecting a rebar pattern from Project Explorer → Columns → Rebar Patterns

Figure: Property Grid for rebars

• In Column Designer, clear cover is defined as the distance up to the outer edge of the main reinforcement bar.

Base Rebar Pattern

The Base Rebar Pattern assignment is required for the calculation of magnified moments.

Key rules for Base Rebar Pattern assignment:

• By default, the first rebar or rebar layout drawn is assigned as the Base Rebar Pattern under the General tab of the Property Grid.

• This field can be toggled only when two or more rebar layouts exist in the section.

• Assigning a rebar layout as the Base Rebar Pattern automatically removes this assignment from the previously assigned layout.

• If the rebar layout currently assigned as the Base Rebar Pattern is deleted, the first rebar layout in the drawing order is automatically assigned as the new Base Rebar Pattern.

Figure: Base Rebar Pattern Option

The Explode Rebar Patterns feature allows a rebar pattern to be broken into its individual rebar points.

To explode a rebar pattern:

• Use Draw Menu → Rebar → Explode

After exploding a rebar pattern:

• Each rebar is converted into an independent rebar point

• Individual rebars can be selected, moved, edited, or deleted separately

This feature is useful when fine control over individual reinforcement placement is required.

Figure: Explode Rebar Pattern Option to convert Patterns in to Individual Points

Columns can be managed within the Project File using the Define Column form.

To access the Define Column form:

• Use Define Menu → Project → Columns, or

• Click the button next to Project Explorer → Columns

The Define Column form allows the user to:

• Add new columns to the Project File

• Rename existing columns

• Remove columns from the Project File

Columns stored in the Project File can be viewed and modified by selecting the desired column from Project Explorer → Columns.

Note on Imported Columns

When columns are imported from ETABS, the Define Menu → Project → Columns option displays a tabular view containing information about all imported columns.
This table provides a convenient way to review and manage multiple imported columns.

Figure: Add Columns to Project File Feature

Composite columns can be created by placing shapes made of different materials directly over one another in the desired configuration.

It is not necessary to create holes before overlapping shapes. Column Designer automatically accounts for overlapping areas when computing section properties and performing analysis and design.

The procedure for moving and positioning shapes within a section is described in Editing Column Cross sections.

Note on Composite Sections

For composite sections:

• Concrete is considered the base material

• Transformed section properties are reported in the Results

Figure: Creating Composite Column Feature in Column Designer

Material properties in Column Designer are defined and managed using the Define Materials form.

To access the Define Materials form:

• Use Define Menu → Project → Materials, or

• Click the button next to Project Explorer → Materials

The Define Materials form, shown in Figure, allows users to view, modify, and add material definitions.

Figure: Define Materials Form

Using the Define Materials Form

The Define Materials form is divided into two main sections:

• Materials Section
  Displays a list of all materials currently defined in the Project File.

• Material Properties Section
  Displays the properties of the selected material.

Material properties can be modified by directly entering the desired values into the available edit boxes.

Adding New Materials

New materials can be added using the Material Library form.

To access the Material Library:

• Click the button provided on the Define Materials form

The Material Library provides predefined materials from multiple regional libraries, including:

• USA

• China

• Europe

Available material types include:

• Concrete

• Reinforcing steel (rebar)

• Structural steel

Selected materials from the Material Library can be added to the Project File and customized as needed.

Figure: Adding New Materials Form

Additional Notes

• Existing material properties can also be modified by selecting materials directly from Project Explorer → Materials.

• The Define Materials form can be accessed at any time during the modeling and design process by clicking on the .

The options available under Define Menu → Stress Strain allow the user to define and manage stress–strain models for concrete and steel materials.

Concrete Stress–Strain and Confinement Models

Click the Concrete button under Define Menu → Stress Strain to access the Define Concrete Confinements form.

This form allows the user to:

• View existing concrete confinement models

• Modify properties of existing confinement models

• Add new confinement models

The form is divided into two main sections:

• Confinement Models section, which lists all available confinement models

• Properties section, which displays the properties of the selected confinement model

Model properties can be modified by directly entering values into the provided edit boxes.

New confinement models can be added using the Add Confinement Model form, which is accessed by clicking the button.
The Add Confinement Model form provides a selection of several predefined confinement models.

The Define Concrete Confinements form can also be accessed by clicking the button next to
Project Explorer → Stress–Strain → Concrete.

Figure: Concrete Stress-Strain and Confinement Models

Steel Stress–Strain Models

Click the Steel button under Define Menu → Stress Strain to access the Define Steel Stress–Strain form.

This form allows the user to:

• View existing steel stress–strain models

• Modify properties of existing models

• Add new stress–strain models

The form contains:

• Stress–Strain Models section listing all available models

• Properties section displaying the properties of the selected model

Model properties can be modified by directly typing values into the edit boxes.

New stress–strain models can be added using the Add Stress–Strain Model form, which is accessed by clicking the button.
The Add Stress–Strain Model form provides a selection of several predefined stress–strain models.

The Define Steel Stress–Strain form can also be accessed by clicking the button next to
Project Explorer → Stress–Strain → Steel.

Figure: Steel Stress-Strain and Confinement Models

Modifying Stress–Strain Models

• Properties of existing concrete confinement models or steel stress–strain models can also be modified by selecting them directly from Project Explorer → Stress–Strain.

• By default:

  • Mander’s Unconfined Model is assigned for concrete

  • Park Strain Hardening Model is assigned for reinforcement

The stress–strain model assigned to a shape can be changed by:

• Selecting the shape in the working area or from Project Explorer → Columns

• Choosing the desired model from the Stress–Strain Curve drop-down list in the Property Grid

The stress–strain model assigned to rebar can be changed from:

• Define Menu → Materials, or

• Project Explorer → Materials

Important Note

Stress–strain and confinement models are used only for moment–curvature analysis.
They do not affect P–M capacity calculations.

Defining the Base Concrete Shape, Base Rebar Pattern, and Base Steel Shape is required for the calculation of Magnified Moments.

According to ACI 318, the equations used to calculate effective stiffness assume:

• A single concrete material

• A single rebar material

• A single steel material

These assumptions are reflected in Equations (1) and (2). However, when a column section contains multiple concrete, rebar, or steel materials, equivalent transformed section properties must be determined.

To achieve this, Column Designer requires the definition of base components for concrete, rebar, and steel so that equivalent values of:

• Ig (concrete)

• Ise (reinforcement)

• Isx (steel)

can be computed separately.

Effective Stiffness Equations (ACI 318)

Where:

• Ec = modulus of elasticity of concrete

• Es = modulus of elasticity of steel

• Ig = gross moment of inertia of concrete

• Ise = transformed moment of inertia of reinforcement

• Isx = transformed moment of inertia of steel

• βdns = factor accounting for sustained axial load

Base Concrete Shape

• By default, the first concrete shape drawn is assigned as the Base Concrete Shape under the General tab in the Property Grid.

• This field can be toggled only when two or more concrete shapes exist in the section.

• Assigning a new Base Concrete Shape automatically removes the assignment from the previously assigned shape.

• If the current Base Concrete Shape is deleted, the first concrete shape in the drawing order is automatically reassigned as the Base Concrete Shape.

Figure: Base Concrete Shape in Column Designer

Base Rebar Pattern

• By default, the first rebar or rebar layout drawn is assigned as the Base Rebar Pattern under the General tab in the Property Grid.

• This field can be toggled only when two or more rebar layouts exist in the section.

• Assigning a rebar layout as the Base Rebar Pattern automatically removes the assignment from the previously assigned layout.

• If the current Base Rebar Pattern is deleted, the first rebar layout in the drawing order is automatically assigned as the new Base Rebar Pattern.

Base Steel Shape

• By default, the first steel shape drawn is assigned as the Base Steel Shape under the General tab in the Property Grid.

• This field can be toggled only when two or more steel shapes exist in the section.

• Assigning a steel shape as the Base Steel Shape automatically removes the assignment from the previously assigned steel shape.

• If the current Base Steel Shape is deleted, the first steel shape in the drawing order is automatically assigned as the Base Steel Shape.

Important Note

The Base Shape and Base Rebar Pattern assignments are critical for correct magnified moment calculations in sections containing multiple materials. Incorrect or missing base assignments may lead to inaccurate stiffness evaluation.

Materials can be assigned to shapes and reinforcement bars by selecting the desired material from the Materials drop-down list in the Property Grid, as shown in Figure.

The Property Grid is activated by:

• Clicking on a shape or rebar in the working area, or

• Selecting a shape or rebar from Project Explorer → Columns

Once activated, the assigned material can be changed by choosing the appropriate material from the Materials drop-down list.

Figure: Property Grid for material assignment

Stress–strain and confinement models can be assigned to concrete shapes, steel shapes, and reinforcement as described below.

Assigning Stress–Strain Models to Shapes

For concrete and steel shapes, the stress–strain model is assigned using the Property Grid.

To assign or change the stress–strain model:

• Select the desired shape by:

  • Clicking on it in the working area, or

  • Selecting it from Project Explorer → Columns

• Once selected, the Property Grid is activated

• Choose the desired model from the Stress–Strain Curve drop-down list

This process is illustrated in Figure.

Figure: Assigning Confinement and Stress-Strain Models

Assigning Stress–Strain Models to Rebars

For rebars, the stress–strain model is assigned at the material level, not directly to individual rebar objects.

To assign or modify the stress–strain model for rebars:

• Click Define Menu → Project → Materials to open the Define Materials form, or

• Select the rebar material from Project Explorer → Materials to activate the Property Grid in the context-sensitive area

Once the Property Grid is active:

• Select the desired stress–strain model from the Stress–Strain Curve drop-down list

This process is illustrated in Figure.

Figure: Property Grid for Rebar Material

Important Clarification

• Stress–strain models assigned to shapes affect the behavior of the section geometry

• Stress–strain models assigned to rebar materials apply to all rebars using that material

• Individual rebars do not have separate stress–strain assignments

Confinement zones can be created in Column Designer using two methods:

• Auto Create Confinement

• Draw Confinement

In this method, the confinement zone is created automatically by the software.

The basic procedure for auto-creating confinement is described below.

Procedure for Auto Creating Confinement Zones

1. Select Column Section
   Select the desired column section from Project Explorer.

Note:
This feature is available only for sections with a single rebar pattern, and supports:

• Rectangular rebar patterns

• Circular rebar patterns

2. Create Auto Confinement Zone
   Click Home Menu → Design → Auto Confinement to create a confinement zone in the selected section.

3. Review and Modify Confinement Geometry
   By default, the confinement zone encloses the outer perimeter of the rebars.

   • Accept the default confinement dimensions, or

   • Modify the dimensions by entering values in the edit boxes under the General tab of the Property Grid

The Property Grid is activated by:

• Selecting the confinement zone in the working area, or

• Selecting it from Project Explorer → Confinement Zones

Figure: Creating Confinement Zones – Auto Confinement

4. Assign Confinement Model
   By default, Mander’s Confined Model is assigned to the confinement zone.

To change the confinement model:

• Select the desired model from the Stress–Strain Curve drop-down list under the General tab of the Property Grid

New confinement models must first be defined using:

• Define Menu → Stress Strain → Concrete, or

• The button next to Project Explorer → Stress-Strain → Concrete

5. Define Tie and Confinement Parameters
   After assigning the confinement model:

   • Select the Stress–Strain tab of the Property Grid

   • Review and modify confinement parameters under the Ties heading, such as:

     • Tie diameter

     • Tie spacing

The total main steel area is computed automatically based on the defined reinforcement.
This value may be modified manually if required.

Figure: Confinement Model and Parameters

6. Review Material Properties
   Under the Materials heading in the Stress–Strain tab:

   • Review the material properties assigned to the confinement zone

   • By default, these properties match those assigned to the main section

   • Modify the values manually if required

Important Notes on Materials and Stress–Strain Models

• Material properties are used for capacity calculations

• Stress–strain and confinement model properties are used for moment–curvature analysis

By default:

• Every concrete or steel shape has a corresponding stress–strain model

• Every rebar material has a corresponding stress–strain model

• Material properties and stress–strain properties are initially identical

However, the user may:

• Assign different material properties to the stress–strain or confinement models

• This does not affect capacity calculations

• This flexibility allows moment–curvature analysis using material strengths higher than design values

Notes Specific to Auto Confinement Zones

• For auto confinement zones:

  • Material properties are initially linked to those of the main section

  • Total main steel area is computed automatically by the program

• Both material properties and steel area may be manually modified if required

• If the section material is changed after creating an auto confinement zone:

  • The user will be prompted to choose whether to update the material properties assigned to the stress–strain model

In this method, Column Designer allows the user to manually draw confinement zones directly on the column section. This approach provides greater flexibility when defining confinement regions.

The basic procedure for drawing confinement zones is described below.

Procedure for Drawing Confinement Zones

1. Select Column Section
   Select the desired column section from Project Explorer.

2. Draw Confinement Zone
   Click:

   • Draw Menu → Confinement → Rectangle, or

   • Draw Menu → Confinement → Circle

Then draw the confinement zone directly on the section using the mouse.

Note:
Only rectangular and circular confinement zones are available.

3. Modify Confinement Geometry
   The dimensions of the confinement zone can be modified by entering values in the edit boxes under the General tab of the Property Grid.

The Property Grid is activated by:

• Selecting the confinement zone in the working area, or

• Selecting it from Project Explorer → Confinement Zones

4. Move Confinement Zone
   The confinement zone can be moved to the desired location using the same methods available for other shapes.

5. Assign Confinement Model
   By default, Mander’s Confined Model is assigned to the confinement zone.

To change the confinement model:

• Select the desired model from the Stress–Strain Curve drop-down list under the General tab of the Property Grid

New confinement models must be defined in advance using:

• Define Menu → Stress Strain → Concrete, or

• The button next to Project Explorer → Stress–Strain → Concrete

6. Define Tie and Confinement Parameters
   After assigning the confinement model:

   • Select the Stress–Strain tab of the Property Grid

   • Review and modify confinement parameters under the Ties heading, including:

     • Tie diameter

     • Tie spacing

     • Total main steel area

All parameters must be entered manually as required.

7. Review Material Properties
   Review the material properties under the Materials heading in the Stress–Strain tab of the Property Grid.

Important Notes for Drawn Confinement Zones

• For manually drawn confinement zones:

  • Material properties are not linked to the material properties of the main section

  • The total main steel area must be calculated and entered manually by the user

• Operations such as:

  • Merging

  • Subtracting

  • Aligning

  • Stacking

can be performed on confinement zones in the same way as for other shapes.

• Merging confinement zones is permitted only when:

  • The zones have the same material properties, and

  • The zones use the same confinement model (rectangular or circular)

• After merging confinement zones:

  • The user must verify all dimensions and parameters in the Stress–Strain tab

  • Modify values as necessary to ensure correctness

Figure: Drawing Confinement Zone Manually

Use the Define Menu → Slenderness → Slenderness Effects toggle to specify whether slenderness effects are to be considered for the current column.

When slenderness effects are enabled:

• Framing Conditions must be defined

• Framing information is used to compute:

  • Effective Length Factors (k)

  • Other parameters required for moment magnification, depending on the selected design code

Supported Design Codes for Slender Columns

Column Designer supports slenderness checks and magnified moment calculations for the following design codes:

• ACI 318-11

• ACI 318-14

• ACI 318-19

• IS 456:2000

• CSA A23-3-14

• BS 8110-97

• Eurocode 2:2004

• AS 3600-2018

When the Slenderness Effects toggle is turned on, use:

Define Menu → Slenderness → Framing Conditions

to access the Column Framing Conditions form.

In this form, select the framing condition that best represents the column end and support conditions, such as:

• Fixed–Fixed

• Fixed–Pinned

• Fixed–Roller

• Fixed–Free

• Pinned–Roller

• Lowest-story framed columns with:

  • Pinned base

  • Fixed base

• Intermediate-story columns connected to frame elements at both ends

Figure illustrates typical column framing conditions relative to the XZ and YZ planes for framed columns.

Figure: Column Framing Conditions

Viewing Framing Conditions

After selecting the framing condition, the framing configuration in the XZ plane is displayed in the working area, as shown in Figure.

The framing view can be displayed in:

• XZ plane

• YZ plane

• 3D view

Use the following tools available in the context-sensitive toolbar:

• XZ / YZ / 3D buttons
  Select XZ or YZ to view and edit framing parameters in the respective plane.
  Select 3D to view the framing condition in three dimensions.

• Zoom In button
  Zoom in to enlarge the framing view.
  Zooming can also be performed using the mouse scroll wheel.

• Zoom Out button
  Zoom out to reduce the framing view size.
  Zooming can also be performed using the mouse scroll wheel.

• Reset and Refresh View button
  Restore the framing display to its default view.

Figure: Framing Conditions View (2D &3D)

The following procedure is used to compute the Effective Length Factors (k).

Procedure for Calculating Effective Length Factors

1. Show Framing Configuration
   Click Define Menu → Slenderness → Show Framing to display the framing conditions.

2. Enter Framing Parameters
   For each plane (XZ and YZ), the Framing Grid (Figure) is activated in the context-sensitive area.
   Enter framing parameters such as:

   • Unsupported length of the column

   • Center-to-center length of columns

   • Length of connecting beams

Notes:

• For Eurocode 2:2004, the stiffness contribution of top and bottom columns is ignored by default.
  A Consider Non-failing Columns toggle is provided to allow inclusion of these columns if desired.

• For BS 8110-97, additional options are available:

  • Simply Supported, Top

  • Simply Supported, Bottom
    These toggles allow beams framing into the column to be treated as simply supported.

3. Select Connected Members
   Select each connected beam or column to activate the Frame Member Grid, where the assigned section properties can be viewed.

By default:

• Program-defined beam framing sections are assigned to beams

• Program-defined column framing sections are assigned to columns

If no changes are required, skip to Step 7.

4. Define Framing Sections
   Click Define Menu → Slenderness → Framing Sections to open the Framing Sections form.

This form allows users to:

• Add new framing sections

• Rename existing sections

• Remove unused sections

5. Edit Framing Section Properties
   Select the desired framing section from
   Project Explorer → Columns → Framing → Sections.

The selected section is displayed in the working area, and the Property Grid is activated.
Modify dimensions and properties as required.

Figure: Defining Framing Sections

6. Review Framing Configuration
   After defining or modifying framing sections, click
   Define Menu → Slenderness → Show Framing to review the updated framing condition.

7. Assign Framing Sections to Members
   Select the connected beam or column whose section is to be changed.
   In the Frame Member Grid, select the desired section from the Section drop-down list.

8. Compute Effective Length Factors
   Once all framing parameters and sections have been assigned correctly, click the Compute button in the Framing Grid to calculate the k-factors.

9. Repeat for Both Planes
   Perform the above steps for both the XZ and YZ planes.
   Alternatively, effective length factors may be entered directly by the user.

Figure: Assigning Framing Section to Members

Additional Notes

• The Framing Conditions, Framing Sections, and Show Framing buttons are active only when Slenderness Effects are enabled.

• The framing view and Framing Grid can also be accessed from:
  Project Explorer → Columns → Framing → Conditions

Figure: Framing Grid

Column Designer provides two modes for defining column loads:

• Simple Loading Mode

• Detailed Loading Mode

Simple loading is intended for short columns where slenderness effects are not considered.
Detailed loading is required for slender columns where moment magnification must be evaluated.

Column Designer automatically opens the Loading form in either Simple Mode or Detailed Mode depending on whether the Slenderness Effects toggle is turned off or on, respectively.

Figure illustrates the loading applied to a column and its cross-section.

Unlimited load combinations can be defined for a column section using:
Define Menu → Loading

Figure: Column Loading on Column and Cross-Section

Sign Convention Used in Column Designer

Axial Load

• Compression is considered positive

• Tension is considered negative

Bending Moment

• For double curvature, top and bottom end moments have opposite signs

• For single curvature, top and bottom end moments have the same sign

This convention is consistent with ETABS.

Simple loading is applicable when:

• The column is designed as a short column

• Slenderness effects are ignored

• Loads and moments have already been magnified by separate analysis (e.g., P-Delta analysis in ETABS)

• Detailed framing or loading information is not available

Defining Simple Load Combinations

For each simple load combination, specify:

• Load combination name

• Axial load (Pu)

• Top and bottom bending moments about:

  • X-axis (Mux)

  • Y-axis (Muy)

Multiple load combinations may be defined as required.

Figure: Defining Simple Load Combinations for Columns

Importing Simple Loads from Text Files

The Import button allows load combinations to be imported from text files.

Required parameter order:

1. Name

2. Axial Load

3. Moment Top (X-axis)

4. Moment Top (Y-axis)

5. Moment Bottom (X-axis)

6. Moment Bottom (Y-axis)

• Parameters must be comma-separated or tab-separated

• Single-space separation is not supported

• Imported values are assumed to use the project unit system

Importing Simple Loads from Excel Spreadsheets

Required column headers (uppercase):

• NAME

• P_U

• M_UXT

• M_UYT

• M_UXB

• M_UYB

Notes:

• Empty cells are assumed to be zero

• Imported values use the project unit system

Exporting Simple Loads

Load combinations can be exported using the Export button.

Text File Format

• Parameters separated by commas

• Same parameter order as import

Excel Spreadsheet Format

• Same column headers as import

• Same parameter order below the header row

Detailed loading is required when slenderness effects are considered.

Load combinations are defined separately for:

• Along X (moments about X-axis)

• Along Y (moments about Y-axis)

General Procedure

• Select the loading direction (Along X or Along Y)

• Specify the load combination name

• Enter code-dependent parameters

• Click the Add button to create additional combinations

• Edit combinations directly in the table as needed

Figure: Defining Loading for Slender Columns

Code-Specific Detailed Loading Requirements

ACI 318-11 / 14 / 19

• Specify axial load and non-sway top and bottom moments

• Click Check under the Check Sway column to open the Sway Conditions form

• Three sway-check methods are available:

  • Stability Index

  • Second-Order Analysis

  • Relative Stiffness of Bracing to Columns

If the column is identified as sway:

• The Consider Sway toggle is activated automatically

• Sway-related input fields become available

Users may manually force a column to be treated as sway by turning on the Consider Sway toggle.

IS 456:2000

• Specify axial load, top moment, and bottom moment

• Perform sway check using the same three methods

• Manual override of sway behavior is permitted

CSA A23-3-04

• Procedure is identical to that used for ACI design codes

Eurocode 2:2004

• Specify axial load, top moment, and bottom moment

• Column is considered braced by default

• Use Consider Unbraced toggle to change this assumption

Important Notes for Eurocode 2

• Moment magnification is not considered for composite sections

• Only rebar area is considered (steel shape area is ignored)

• Parameters for magnification may be specified under:

  • Options Menu → Partial Safety Factors

  • Options Menu → Slenderness Parameters

BS 8110-97

• Specify axial load, top moment, and bottom moment

• Column is considered braced by default

• Use Consider Unbraced toggle to change this assumption

AS 3600-2018

• Specify:

  • Axial load

  • Top and bottom moments

  • Loading factor

• Column is considered braced by default

• Use Consider Unbraced toggle to activate sway-related inputs

Note:
The loading factor is the ratio of axial load due to:

• Permanent actions (dead load)

• Imposed actions (live load)

as defined in AS 3600-2018 Clause 10.4.3(2).

Viewing Final Design Loads

Final design loads after moment magnification can be viewed from:

• Results Menu → Capacity → Design Loads, or

• Project Explorer → Results → Capacity → Design Loads

Figure: Viewing Final Design Loads

Click the Check button under the Check Sway column to access the Sway Conditions form shown in Figure.

Figure: Sway Conditions Form

Available Sway Check Methods

Stability Index

• Evaluated at the story level

• If Q ≤ 0.05, the story is classified as non-sway

• Requires:

  • Story load

  • Story shear

  • Relative lateral deflection

  • Column center-to-center length

Second-Order Analysis

• Column is considered non-sway if second-order moments do not exceed first-order moments by more than 5%

• Requires first- and second-order end moments

Relative Stiffness of Bracing to Columns

• Column is non-sway if:

  • Stiffness ratio ≥ 12

• Requires:

  • Sum of stiffness of bracing elements

  • Lateral stiffness of the column

When a column is classified as sway:

• Parameters are transferred automatically to the sway part of the Loading form

• Values may be edited if required

The Column Auto Design feature, available under Home Menu → Auto Design, is a powerful and efficient tool for designing column reinforcement with or without considering slenderness effects.

This feature automatically designs the column reinforcement in accordance with the design parameters specified by the user and the selected design code.

The Auto Design tool uses an iterative optimization process to identify the minimum reinforcement and reinforcement layout that satisfies the user-defined maximum capacity (D/C) ratio for the governing load combination (i.e., the load combination producing the highest D/C ratio).

Applicability and Limitations

Column Auto Design is available only for:

• Rectangular reinforced concrete columns

• Circular reinforced concrete columns

• Columns with only one rectangular or circular rebar pattern

Additional notes:

• Auto Design is supported for columns imported from ETABS only if they contain a single rectangular or circular rebar pattern.

• Columns imported from CDB files are imported as polygonal sections; therefore, Auto Design is not available for such columns.

Procedure for Column Auto Design

Step 1: Select Column

Select the desired column from the Project Explorer.

Step 2: Open Auto Design

Click the Auto Design button to access the Design Form.

Figure: Column Designer Auto Design Feature

Step 3: Define Rebar Selection Parameters

Accept the default values or modify them as required using the available input fields and toggles:

• Smallest Bar
  Specifies the minimum rebar size allowed in the design.

• Largest Bar
  Specifies the maximum rebar size allowed in the design.

• Clear Cover
  Specifies the minimum clear cover to be provided in the section.

• Clear Spacing
  Specifies the minimum clear spacing required between rebars.

• Maximum Rebar Ratio
  Specifies the upper limit for the reinforcement ratio.

• Maximum D/C Ratio
  Specifies the maximum allowable capacity ratio that must be satisfied by the design.

• Follow Provided Layout

  • When ON, the rebar layout remains fixed and only the bar size is increased.

  • When OFF, the number of bars may be increased while satisfying spacing requirements.

• Allow Bundled Bars

  • When ON, bundled bars are permitted if single bars cannot satisfy the D/C limit.

  • When OFF, bundled bars are not allowed.

• Status
  Displays the current design status:

  • Run Design – Design has not yet been executed

  • Success – Design completed successfully

  • Failed – D/C ratio limit cannot be satisfied with current settings

Step 4: Run Auto Design

Click the Run button to start the auto design process.

Step 5: Review Design Iterations

During the iterative process, Column Designer displays:

• Current rebar layout

• Governing load combination

• Rebar ratio

• Current capacity (D/C) ratio

The displayed information updates automatically for each iteration based on the rebar selection settings.

• A “Success” status indicates that the design requirements have been satisfied.

• A “Failed” status indicates that the specified D/C ratio limit cannot be achieved using the current rebar selection settings.

If the design fails:

• Adjust the rebar selection parameters

• Re-run the Auto Design process until a Success status is achieved

This section describes how to use the various tools available in Column Designer to edit shapes and to add, edit, and distribute reinforcement within a column section.

After a shape has been added to a column section, its dimensions and properties can be modified. The editing procedure depends on the type of shape used. In Column Designer, shapes are broadly classified into the following two categories based on how they are created.

Parametric Shapes

Parametric shapes are shapes whose geometry is defined using a set of parameters (such as width, depth, radius, or flange thickness). These shapes include:

• Rebar pattern shapes

• Basic steel shapes defined parametrically

• Basic concrete shapes defined parametrically

• Standard steel shapes obtained from the built-in shape databases

Parametric shapes are typically created using one of the following methods:

• Quick Design Wizard

• File Menu → Rectangular Model

• File Menu → Circular Model

• Selecting shapes from one of the available Shape Libraries and adding them to the current section

Note: The Polygon shape is not considered a parametric shape.

Converting Parametric Shapes to Polygon Shapes

Parametric shapes can be converted into non-parametric (polygon) shapes using the following command:

• Edit Menu → Edit → Edit Points

Once converted, the user can:

• Add nodal points

• Remove nodal points

• Modify nodal point coordinates directly

This conversion provides full geometric flexibility when parametric editing is no longer sufficient.

Figure: Converting Parametric Shapes to Polygon Shapes

Non-Parametric Shapes

Non-parametric shapes are shapes whose geometry is defined explicitly by their nodal coordinates rather than by parameters. These shapes are created in the following ways:

• Drawing directly in the working area using
  Draw Menu → Concrete Shapes → Polygon

• Modifying library-based or parametric shapes by:

  • Flipping shapes

  • Merging multiple shapes

  • Creating holes

  • Performing other geometric operations to achieve the desired shape

• Defining shapes by manually inputting or importing coordinate data

Non-parametric shapes offer complete geometric freedom but do not retain the parametric controls available for standard shapes.

The dimensions and position of parametric shapes can be modified using the Property Grid. The Property Grid is activated in the context-sensitive area when a shape is selected, either by:

• Clicking directly on the shape in the working area, or

• Selecting the shape from Project Explorer → Columns

Once activated, the Property Grid allows the user to edit geometric parameters such as dimensions, location, and other shape-specific properties.

Figure illustrates the Property Grid associated with parametric shapes.

Figure: Property Grid for Parametric Shapes

Editing Parametric Shapes Using Edit Points

Parametric shapes can also be edited using the following command:

Edit Menu → Edit → Edit Points

This option allows the user to:

• Add nodal points

• Remove nodal points

• Modify existing nodal point coordinates

However, editing a parametric shape using Edit Points requires the shape to be converted into a polygon (non-parametric shape). Once converted, the shape will no longer retain its parametric behavior, and further modifications must be performed by directly editing nodal coordinates rather than by adjusting parameters.

The dimensions of non-parametric shapes can be edited by modifying their nodal point coordinates. This is done using the following command:

Edit Menu → Edit → Edit Points

This option allows the user to:

• Add nodal points

• Remove nodal points

• Modify existing nodal point coordinates

In addition, the dimensions of the shape and any internal holes can be edited directly from the Property Grid:

• Points tab: Used to edit the coordinates of the shape boundary

• Holes tab: Used to edit the coordinates and properties of holes within the shape

The Property Grid is activated in the context-sensitive area when a shape is selected, either by:

• Clicking on the shape in the working area, or

• Selecting the shape from Project Explorer → Columns

Figure shows the Property Grid for non-parametric shapes.

Figure: Property Grid for Non-Parametric Shapes

Graphical alignment allows shapes to be aligned without requiring any text or numeric input from the user. Shapes can be aligned graphically using the alignment tools available in the Edit Menu.

To align shapes graphically, follow the steps below:

1. Select the shapes to be aligned in the working area or from the Project Explorer.

2. Choose the appropriate alignment button from the available options.

Alignment Options

• Align Left
  Aligns the selected shapes along their left edge.
  Alignment is performed with respect to the lowest x-coordinate among the selected shapes.

• Align Right
  Aligns the selected shapes along their right edge.
  Alignment is performed with respect to the highest x-coordinate among the selected shapes.

• Align Center
  Aligns the selected shapes along the vertical centerline.
  Alignment is performed with respect to the x-centroid of the selected shapes.

• Align Top
  Aligns the selected shapes along their top edge.
  Alignment is performed with respect to the highest y-coordinate among the selected shapes.

• Align Bottom
  Aligns the selected shapes along their bottom edge.
  Alignment is performed with respect to the lowest y-coordinate among the selected shapes.

• Align Middle
  Aligns the selected shapes along the horizontal centerline.
  Alignment is performed with respect to the y-centroid of the selected shapes.

Figure: Alignment Options for Shapes

Column Designer provides options to flip shapes about horizontal or vertical axes using the tools available under the Edit Menu → Flip.

To flip a shape:

1. Select the shape to be flipped in the working area or from the Project Explorer.

2. Click the appropriate flip button from the Edit Menu.

Flip Options

• Flip Horizontal
  Flips the selected shape about the vertical axis, creating a mirror image left-to-right.

• Flip Vertical
  Flips the selected shape about the horizontal axis, creating a mirror image top-to-bottom.

Figure: Flip Options for Shapes

Note

After a shape is flipped, it is converted into a polygon (non-parametric shape). Once converted, the shape can no longer be edited parametrically and must be modified by editing its nodal coordinates.

Stacking is performed based on the relative position of the selected shapes. To stack shapes, first select the desired shapes and then choose the appropriate stacking option from the Edit Menu.

Stacking Options

• Stack Horizontal
  Stacks the selected shapes side by side horizontally.
  The y-coordinates remain unchanged, and the shapes are arranged along the x-direction.

• Stack Vertical
  Stacks the selected shapes vertically, one on top of another.
  The x-coordinates remain unchanged, and the shapes are arranged along the y-direction.

Figure: Stack Options for Shapes

Two shapes can be merged if they:

• Have the same material properties, and

• Share a common edge or overlap with each other.

To merge shapes:

1. Select the shapes to be merged.

2. Click Edit Menu → Merge.

3. Verify the geometry of the merged shape.

Note:
After merging, the shapes are converted into a single editable polygon (non-parametric shape).

Figure: Merge Option for Shapes

Holes can be created in a shape or section by subtracting one or more shapes from a main shape.

To create a hole:

1. Select the main shape to which the hole will be added.

2. While holding the Ctrl or Shift key, select the shape(s) to be subtracted.

3. Click Edit Menu → Merge → Subtract.

Note:

• The subtract operation is selection-order dependent. The first selected shape is treated as the main shape, and all subsequently selected shapes are subtracted from it.

• After subtraction, the resulting shape is converted into an editable polygon.

• The dimensions and location of the hole can be modified from the Property Grid → Holes tab.

Figure: Creating Holes in Shapes

Selected shapes can be moved either graphically using the mouse or numerically using displacement values.

Move Shapes Using the Mouse

1. Click Edit Menu → Select to activate Selection Mode.

2. Select a single shape or multiple shapes (use Ctrl or Shift for multi-selection).

3. Hold down the left mouse button and drag the shapes to the desired location.

Move Shapes by Displacement Values

1. Click Edit Menu → Select to activate Selection Mode.

2. Select the shape(s) to be moved.

3. Click Edit Menu → Edit → Move Sections to open the Move Points form.

4. Enter the displacement values in the X (dx) and Y (dy) directions.

Figure: Moving Shapes by Displacement Values

This section describes how to obtain and interpret the various analysis and design results generated by Column Designer. The available result options allow users to evaluate column behavior, capacity, and adequacy under different loading conditions.

It is assumed that the user is familiar with the basic concepts of:

• Column design and analysis

• Structural concrete mechanics

• Interpretation of structural analysis results and design parameters

This section focuses on presenting and interpreting the following types of results:

• Displaying geometric properties and other section-related results

• Plotting flexural stress distributions for various load combinations

• Generating interaction curves and interaction surfaces

• Plotting moment–curvature relationships

• Checking the adequacy and capacity of a column section for different load combinations

To view a summary of the overall dimensions and geometric properties of the current column section, use one of the following options:

• Results Menu → Section → Section Properties, or

• Project Explorer → Columns → Results → Section → Section Properties

These options open the Section Properties form, which presents detailed geometric information for the selected column section.

Section Properties Form

The Section Properties form is divided into the following three sections:

• Basic Properties
  Includes the section area, shear areas, moments of inertia, and torsional constant.

• Section Bounds
  Includes the overall dimensions of the section and the centroid location with respect to both the global origin and the local origin.

• Additional Properties
  Includes the radii of gyration and section moduli of the selected section.

Context-Sensitive Toolbar Options

The following tools are available in the context-sensitive toolbar when viewing Section Properties:

• Zoom In
  Enlarges the view of the section. Zooming in can also be performed by scrolling the mouse wheel upward.

• Zoom Out
  Reduces the view of the section. Zooming out can also be performed by scrolling the mouse wheel downward.

• Reset and Refresh View
  Restores the section display to its original default view.

• Add to Report
  Adds the displayed section properties to the detailed design report.

Note

For composite sections, concrete is treated as the base material, and all reported geometric properties are presented as transformed section properties.

Figure: Viewing Section Properties

The Load Points feature displays the location of applied loads on a column section at the upper and lower ends of the column. The position of each load point depends on the direction of load eccentricities along the local 3-axis and local 2-axis of the section.

This feature helps visualize how axial load and bending moments act on the column cross-section for different load combinations.

Displaying Load Points

To display the load point locations and associated eccentricities, follow the steps below:

1. Create the column section for which the load points are to be viewed.

2. Define the load combinations for the column section.

3. Click Results Menu → Section → Load Points, or
   Project Explorer → Columns → Results → Section → Load Points.

4. Select the desired load combination and section location from the Load Points Grid (Figure 5.1) that appears in the context-sensitive area.

5. Choose to view the load points in 2D or 3D using the options available in the context-sensitive toolbar (Figure 5.2).

6. The eccentricities of the load points are displayed along the local 3-axis and local 2-axis of the column section.

Context-Sensitive Toolbar Options

The following tools are available when viewing Load Points:

• 2D
  Displays the load point locations in a two-dimensional view.

• 3D
  Displays the load point locations in a three-dimensional view.

• Zoom In
  Enlarges the view of the load points. Zooming in can also be performed by scrolling the mouse wheel upward.

• Zoom Out
  Reduces the view of the load points. Zooming out can also be performed by scrolling the mouse wheel downward.

• Reset and Refresh View
  Restores the load point display to its default view.

• Add to Report
  Adds the load point information to the detailed design report.

Figure: Displaying Load Point and Load Points Grid

After a column section has been created and load combinations have been defined, Column Designer can display flexural stresses on the section as 2D or 3D color-coded contours in the working area.

This feature helps visualize stress distribution across the column cross-section for different load combinations and section locations.

Displaying Section Elastic Stresses

To display elastic stresses on a column section, follow the steps below:

1. Create the column section for which stresses are to be viewed.

2. Define the load combinations for the section.

3. Click Results Menu → Section → Section Stresses, or
   Project Explorer → Columns → Results → Section → Section Stresses.

4. Select the desired load combination and section location from the Section Elastic Stresses Grid that appears in the context-sensitive area.

5. Choose to view the stresses in 2D or 3D using the options available in the associated context-sensitive toolbar.

6. To read the stress value at any location, hover the mouse cursor over the desired point on the section.
   A color-coded legend displayed on the right side of the working area helps interpret the stress values.

Context-Sensitive Toolbar Options

The following tools are available when viewing Section Elastic Stresses:

• 
  Displays the section stresses in a two-dimensional view.

• 
  Displays the section stresses in a three-dimensional view.

• Zoom In
  Enlarges the stress display. Zooming in can also be performed by scrolling the mouse wheel upward.

• Zoom Out
  Reduces the stress display. Zooming out can also be performed by scrolling the mouse wheel downward.

• Reset and Refresh View
  Restores the section stress display to its default view.

• Add to Report
  Adds the displayed section stresses to the detailed design report.

Figure: Section Elastic Stresses and Grid

For a given strain profile on a column cross-section, three stress resultants can be determined:

• Axial load (P)

• Bending moment about the local 3-axis (M₃)

• Bending moment about the local 2-axis (M₂)

As the strain profile varies, the corresponding values of these stress resultants also vary. By plotting the three stress resultants in a three-dimensional space, a continuous surface is generated that represents all possible combinations of P, M₃, and M₂ for the cross-section. This surface is known as the Stress Resultant Interaction Surface.

Capacity (Failure) Surface

When the strain profiles used to generate the interaction surface correspond to material failure conditions, the resulting surface is referred to as the Capacity Surface or Failure Surface.

• Any combination of applied actions (P, M₃, M₂) that lies inside the volume enclosed by this surface is considered safe.

• Any combination that produces a point outside this surface is considered unsafe.

Because the interaction surface exists in three-dimensional space, it cannot be represented directly on a two-dimensional plot. However, it can be visualized through two-dimensional interaction curves obtained by slicing the surface in specific planes.

Interaction Curves Derived from the Capacity Surface

The two most commonly used curves derived from the interaction surface are described below.

Load–Moment Interaction Curve (P–M Curve)

A P–M interaction curve is obtained by slicing the capacity surface vertically at a specified angle about the origin. This produces a two-dimensional plot showing the relationship between:

• Axial load capacity (P), and

• Resultant bending moment capacity (M)

P–M curves are widely used for the design and assessment of columns. Special P–M curves can be generated by slicing the capacity surface along the local 3-axis or local 2-axis, providing insight into column behavior under uniaxial bending.

Moment–Moment Interaction Curve (M–M Curve)

A Moment–Moment (M–M) interaction curve is obtained by slicing the capacity surface on the local 2–3 plane. This produces a plot of:

• Moment capacity about the local 3-axis (M₃) versus

• Moment capacity about the local 2-axis (M₂)

The M–M interaction curve illustrates how the moment capacity varies around the cross-section at a given axial load level and provides valuable insight into the biaxial bending behavior of the column section.

The variation of the three parameters governing the capacity of a column section—axial load (P), moment about the local 3-axis (M₃), and moment about the local 2-axis (M₂)—can be displayed together in a single three-dimensional interaction diagram.

In this representation:

• P is plotted along the vertical axis, and

• M₃ and M₂ are plotted along two orthogonal horizontal axes.

This provides an overall view of the combined axial–biaxial bending capacity of the column section.

Generating Interaction Diagrams

To generate and view interaction surfaces and curves for a column section, follow the steps below:

1. Define the column section geometry and material properties (refer to Chapter 3 for details).

2. Click Results Menu → Capacity → Interaction Diagram, or
   Project Explorer → Columns → Results → Capacity → Interaction Diagram.

3. Selecting this option activates the Interaction Diagram Settings Grid in the context-sensitive area, where display options—such as inclusion or exclusion of strength reduction factors (or partial safety factors)—can be adjusted.

4. After modifying the desired settings, click Refresh to update the interaction diagrams.

Notes

1. Strength reduction factors (or partial safety factors) specific to the selected design code can be modified from
   Options Menu → Strength Reduction Factors (or Partial Safety Factors, depending on the code).

2. The stirrup type (tied or spiral) can be specified from Define Menu → Stirrup Type.

3. The number of curves generated in the interaction diagram can be controlled from
   Options Menu → Diagrams → Curves.

   • Default value: 32 curves, each at 11.25° neutral-axis rotation.

4. The number of points displayed on each curve can be adjusted from
   Options Menu → Diagrams → Points.

   • Default value: 25 points per curve.

Interaction Diagram Display

The working area is divided into three sections, each with its own toolbar, as shown in Figure.

Figure: Interaction Diagram Screen

Each section and its associated tools are described below.

Interaction Surface

The Interaction Surface displays the variation of axial load capacity and biaxial moment capacity in a color-coded 3D plot.

• Pᵤ is plotted along the vertical axis.

• M₃ and M₂ are plotted along the horizontal axes.

This visualization provides a complete overview of the section’s capacity.

Interaction Surface Toolbar Options

• Interaction Surface Drop-Down List
  Select whether the surface coloring represents Pᵤ, M₂, or M₃.
  A color legend is shown on the right side to assist interpretation.

• Zoom In
  Enlarges the interaction surface view. Mouse scroll-up can also be used.

• Zoom Out
  Reduces the interaction surface view. Mouse scroll-down can also be used.

• Reset and Refresh View
  Restores the interaction surface to the default display.

• Add to Report
  Adds the interaction surface to the detailed design report.

P–M Curves

P–M curves are obtained by slicing the interaction surface with a vertical plane at specified neutral-axis angles. Each curve represents the relationship between axial load and resultant bending moment.

P–M Curve Toolbar Options

• Angle Drop-Down List
  Displays available neutral-axis angles and user-defined load combinations.
  If a load combination is selected and the corresponding point lies within the curve, the section is adequate for that load.
  Moving the cursor over the curve displays numerical values at any point.

• Tabulated Output
  Displays the numerical data for the selected curve.
  The data may be exported to Excel or copied to the clipboard.

• Add to Report
  Adds the displayed P–M curve to the detailed report.

• Interaction Curve Details
  Opens the Interaction Curve Details form, showing information such as neutral-axis angle, maximum compression and tension capacity, and maximum moment capacity.

M–M Curves

M–M curves are obtained by slicing the interaction surface with a horizontal plane at a specified axial load level (Pᵤ). These curves represent the biaxial bending capacity at a given axial load.

M–M Curve Toolbar Options

• Pᵤ Value Edit Box
  Enter the axial load level for which the M–M curve is to be displayed.
  The curve updates automatically.

• Tabulated Output
  Displays numerical data for the curve, which can be exported or copied.

• Add to Report
  Adds the M–M curve to the detailed report.

• Interaction Curve Details
  Displays maximum and minimum moment capacities about the local 2- and 3-axes.

The Animate Interaction feature allows users to visualize the generation of the capacity interaction surface as the neutral axis angle varies.

To view the interaction animation:

• Click Results Menu → Capacity → Animate Interaction, or

• Select Project Explorer → Columns → Results → Capacity → Animate Interaction

This opens an animated display showing how the interaction surface is formed for different neutral axis orientations.

Animation Toolbar Options

The following tools are available in the animation toolbar:

• Play / Stop
  Click Play to start the animation.
  While the animation is running, the button changes to Stop , which can be clicked to pause the animation.

• Zoom In
  Enlarges the interaction surface display. Zooming in can also be performed by scrolling the mouse wheel upward.

• Zoom Out
  Reduces the interaction surface display. Zooming out can also be performed by scrolling the mouse wheel downward.

• Reset and Refresh View
  Restores the interaction surface display to its original default view.

Figure: Animate Interaction Diagram Screen

The Capacity Point Details feature provides detailed information at selected points along the P–M interaction diagram, either for a specified neutral axis angle (with respect to the X-axis) or for a selected load combination.

To access this feature, use one of the following options:

• Results Menu → Capacity → Capacity Point Details, or

• Project Explorer → Columns → Results → Capacity → Capacity Point Details

Capacity Point Details Display

The working area is divided into two sections, each with its own toolbar:

• Left Section: P–M Curve display

• Right Section: Stress/Strain Contour display

As the cursor is moved along points on the P–M curve in the left section, the corresponding capacity point information is displayed in the Capacity Point Details Grid in the context-sensitive area. At the same time, the associated stress or strain contour is displayed in the right section.

The following information may be displayed for each capacity point:

• Point status

• Axial load

• Major bending moment

• Force and moment contributions from concrete and reinforcement

• Strain values in concrete and reinforcement

Interpretation of Capacity Point Details

The capacity point details provide valuable insight into the behavior of the column section:

• By examining the Point Status, it can be determined whether the capacity point lies in a:

  • Compression-controlled zone, or

  • Tension-controlled zone

• In the compression-controlled zone, failure is initiated by crushing of concrete at the highly compressed edge of the section.

• In the tension-controlled zone, failure is initiated by yielding of the outermost longitudinal reinforcement on the tension side of the neutral axis.

• The rebar strain and rebar force values are particularly useful for determining appropriate lap splice requirements, such as whether compression lap splices or tension lap splices are required in different regions of the P–M diagram.

P–M Curve Section Toolbar Options

The toolbar associated with the P–M curve section provides the following options:

• Angle Drop-Down List
  Displays available neutral axis angles and all user-defined load combinations.
  If the section is adequate for the selected load combination, the load vector lies within the P–M curve, indicating available reserve capacity.
  Selecting an angle or load combination updates the P–M curve automatically.
  Moving the cursor over the curve displays values at any point.

• Tabulated Output
  Displays the numerical data for the currently displayed curve.
  The data can be exported to Excel or copied to the clipboard.

• Add to Report
  Adds the capacity point details to the detailed design report.

• Interaction Curve Details
  Opens the Interaction Curve Details form, which displays information such as:

  • Neutral axis angle

  • Maximum compression capacity

  • Maximum tension capacity

  • Maximum moment capacity

Stress/Strain Contour Section Toolbar Options

The toolbar associated with the stress/strain contour section includes the following options:

• 
  Displays the stress or strain contour in two-dimensional view.

• 
  Displays the stress or strain contour in three-dimensional view.

• Type of Contour Drop-Down List
  Allows selection of the contour type to be displayed. Available options include:

  • Concrete stress

  • Bar stress

  • Concrete strain

  • Bar strain

Figure: Capacity Point Details Screen

The Multiple Curves feature helps evaluate the influence of key design parameters—such as compressive strength of concrete, tensile strength of reinforcement, and rebar size—on the capacity of a column cross-section.

This feature is especially useful for:

• Understanding sensitivity of section capacity to material and reinforcement changes

• Identifying the most effective way to improve capacity when a section is found to be inadequate for the given load combinations

Accessing Multiple Curves

To access the Multiple Curves feature, click:

• Results Menu → Capacity → Multiple Curves

This opens the Multiple Curves form, which allows plotting multiple P–M or M–M diagrams on the same graph while varying selected parameters.

Curve Type Options

Select the desired curve type from the following options:

• P–M₃ (Angle = 0°)
  Plots a P–M interaction diagram at a neutral axis angle of 0 degrees.

• P–M₂ (Angle = 90°)
  Plots a P–M interaction diagram at a neutral axis angle of 90 degrees.

• P–Mₙ (Specified Neutral Axis Angle)
  Plots a P–M interaction diagram at a user-specified neutral axis angle.
  Selecting this option requires choosing the desired angle from a drop-down list.

• P–Mₙ (Specified Load Combination)
  Plots the P–M interaction diagram corresponding to a selected load combination.
  All previously defined load combinations are available in the drop-down list.

• M₃–M₂ (Specified Axial Load, Pᵤ)
  Plots an M–M interaction curve at a specified axial load level.
  Selecting this option requires entering the desired axial load value (Pᵤ).

Varying Parameters and Generating Curves

1. Select the Variable Type to be varied, such as:

   • Compressive strength of concrete (f′c)

   • Steel tensile strength (fᵧ)

   • Rebar size

2. Set the remaining options as required for the selected curve type.

3. Click the Refresh button to generate and display the multiple curves on the same graph.

The resulting plots allow easy comparison of section capacity under different material and reinforcement scenarios.

Figure: Multiple Curves Feature in Column Designer

The Design Loads feature displays the final loads used for design after all required adjustments have been applied.

To access the Design Loads form, use one of the following options:

• Results Menu → Capacity → Design Loads, or

• Project Explorer → Columns → Results → Capacity → Design Loads

This opens the Final Design Loads form, where the loads actually considered in the design checks can be reviewed.

Final Design Loads

For slender columns, the final design loads may differ from the user-defined input loads, as they are modified to account for second-order (moment magnification) effects in accordance with the selected design code.

To view the design loads in a specific direction:

• Select the Along X tab to view moments about the X-axis, or

• Select the Along Y tab to view moments about the Y-axis

The moments displayed under the Along X and Along Y tabs correspond to bending about the respective global axes.

Figure: Final Design Load Combinations

After a column section has been defined (geometry and material properties), it is checked for adequacy against all specified load combinations based on the capacity ratio.

The capacity ratio is defined as the ratio of the applied actions to the corresponding capacity of the cross-section.

For members with a single governing action (such as beams under bending), capacity ratios are straightforward to define. However, for column sections subjected simultaneously to axial load and biaxial bending, the definition of capacity and capacity ratio is more complex. As a result, multiple capacity ratio formulations can be defined.

Column Designer computes capacity ratios using the following methods.

Moment Sum at P

The Moment Sum at P method defines the capacity ratio as the sum of the individual ratios of applied moments to the corresponding maximum moment capacities about each principal axis for a given axial load $P_{u}$.

The moment capacity about each axis is obtained by slicing the capacity interaction surface at the specified axial load to generate an M–M interaction curve.

Figure illustrates the capacity ratio calculation based on the Moment Sum at P method.

Figure: Capacity Ratio Based on Moment Sum at P

Moment Vector at P

The Moment Vector at P method defines the capacity ratio as the ratio of the length of the applied moment vector to the length of the moment capacity vector at the specified axial load $P_{u}$.

As with the previous method, the moment capacity vector is obtained from the M–M interaction curve corresponding to the given axial load.

Figure illustrates the capacity ratio calculation based on the Moment Vector at P method.

Figure: Capacity Ratio Based on Moment Vector at P

Axial Compression (P)

For pure axial compression, the capacity ratio is defined as the ratio of the applied compressive axial load to the maximum compressive axial load capacity in the absence of bending moments.

\text{Capacity Ratio}_{\text{compression}} = \frac{P_{u}}{\phi P_{n0}}

where:

• $P_{u}$= applied axial load

• $\phi P_{n0}$= design axial compression capacity without bending

Axial Tension (P)

For pure axial tension, the capacity ratio is defined as the ratio of the applied tensile axial load to the maximum tensile axial load capacity in the absence of bending moments.

\text{Capacity Ratio}_{\text{tension}} = \frac{P_{u}}{\phi P_{n0}}

P–M Vector Method

The P–M Vector method defines the capacity ratio as the ratio of the length of the applied action vector (combining axial load and bending moments) to the length of the capacity vector in the same direction.

This approach evaluates adequacy directly in the combined axial–moment space.

Figure illustrates the capacity ratio calculation based on the P–M Vector method.

Figure: Capacity Ratio Based on P–M Vector

Capacity check results are presented in terms of capacity ratios. The results are reported separately for the top end, bottom end, and for combined effects in both directions of the column.

The Capacity Calculation Results form is shown in Figure.

Displaying Capacity Ratio Results

To view the capacity ratio results, follow the steps below:

1. Define the column cross-section for which capacity is to be checked.

2. Click Results Menu → Capacity → Capacity Ratios, or
   Project Explorer → Columns → Results → Capacity → Capacity Ratios.

This opens the Capacity Calculation Results form.

Interpreting the Results

• The maximum capacity ratios calculated using different methods are displayed in separate tabs for the top and bottom ends of the column section.

• For each load combination, the software indicates whether the section is adequate or inadequate.

• If the maximum capacity ratio exceeds 1.0, the section is reported as inadequate for the corresponding load combination.

• The tabulated results can be:

  • Exported to an Excel file using the Export button, or

  • Copied to the clipboard using the Copy button.

Figure: Capacity Calculation Results Form

Notes

1. The capacity ratio calculated using the Moment Sum at P method is excluded when determining the governing (maximum) capacity ratio.

2. Capacity ratios are calculated from the interaction surface with capacity reduction factors included, in accordance with the selected design code.

The Detailed Results feature provides comprehensive capacity evaluation information for each load combination, in addition to the governing capacity ratios.

To access the detailed results, use one of the following options:

• Results Menu → Capacity → Detailed Results, or

• Project Explorer → Columns → Results → Capacity → Detailed Results

This opens the Detailed Capacity Calculation Results form, shown in Figure.

Detailed Capacity Calculation Results

The Detailed Capacity Calculation Results form displays the following additional information for each load combination:

• Resultant bending moment

• Resultant moment angle

• Neutral axis angle

• Neutral axis depth

• Capacity ratios calculated using all available methods

The tabulated results can be:

• Exported to an Excel file using the Export button, or

• Copied to the clipboard using the Copy button

Figure: Detailed Capacity Calculation Results Form

Notes

1. If the specified axial load exceeds the maximum axial load capacity, the capacity ratios computed using the Moment Sum at P and Moment Vector at P methods display very large values (typically 200 and 100, respectively), indicating that the section is inadequate.

2. Capacity ratios are calculated from the interaction surface with capacity reduction factors included, in accordance with the selected design code.

3. The neutral axis depth is calculated for the nominal moment corresponding to the factored axial force on the relevant P–M interaction curve, based on the direction of bending.

The Stress–Strain for Loading feature allows the user to view the stress and strain contours in concrete and reinforcement, along with the orientation and location of the neutral axis, for a selected load combination.

To access this feature, use one of the following options:

• Results Menu → Capacity → Stress Strain for Loading, or

• Project Explorer → Columns → Results → Capacity → Stress Strain for Loading

Display Options

Once activated, the stress–strain contours are displayed in the working area. The associated toolbar provides the following options:

• Load Combination drop-down list
  Select the desired load combination for which the stress–strain state is to be displayed.

• 2D button
  Displays the stress/strain contours in 2D view.

• 3D button
  Displays the stress/strain contours in 3D view.

• Type of Contour drop-down list
  Select the type of contour to display. The available options are:

  • Concrete stress

  • Bar stress

  • Concrete strain

  • Bar strain

Notes

1. When the axial load is non-zero, the stress–strain state for loading is determined based on the eccentricity angles.

2. When the axial load is zero, the stress–strain state for loading is determined based on the moment angles.

3. If the selected load combination lies outside the interaction surface (i.e., the applied demand exceeds the section capacity), the Stress–Strain for Loading may not be computed.

4. The neutral axis depth is calculated for the factored axial force and factored moment using the moment–curvature curve corresponding to the resultant moment angle.

Figure: Stress-strain contours for Given Loading

The Loading Capacity feature provides a visual comparison between the applied loading and the section capacity for a selected column. The results can be viewed in both 2D and 3D, allowing users to clearly assess whether the applied loads lie within the capacity envelope of the section.

To access this feature, use one of the following options:

• Results Menu → Capacity → Loading Capacity, or

• Project Explorer → Columns → Results → Capacity → Loading Capacity

Display Options

When the Loading Capacity view is activated, the following toolbar options are available:

• Load Combination Drop-Down List
  Select the load combination for which the loading and capacity are to be displayed.

• Show Loading / Capacity Drop-Down List
  Choose the desired display option:

  • Loading – Displays only the applied load vector

  • Capacity – Displays only the section capacity envelope

  • Loading and Capacity – Displays both the applied loading and the capacity together for direct comparison

Figure: Viewing Loading Capacity Feature

The moment–curvature diagram is a graphical representation of the relationship between the moment resistance of a cross-section and its curvature. A moment–curvature diagram is derived from stress resultants and is independent of member geometry or bending moment distribution. For a specified axial load, it represents a fundamental property of the cross-section.

The moment–curvature relationship is a critical input for:

• Nonlinear static analysis

• Nonlinear dynamic analysis

• Evaluation of post-elastic behavior

• Determination of plastic hinge rotational capacity under high seismic demand

This relationship also forms the basis of capacity-based and performance-based design methodologies.

Displaying the Moment–Curvature Diagram

Column Designer allows users to generate and display moment–curvature curves for a column section.

To access this feature:

• Click Results Menu → Results → Moment Curvature → Moment Curvature, or

• Use Project Explorer → Columns → Results → Moment Curvature → Moment Curvature

Once activated, the Moment Curvature Diagram is displayed in the working area.

Figure: Moment Curvature Diagram

Diagram Settings

Activating the Moment Curvature command opens the Diagram Grid in the context-sensitive area. This grid allows the user to control the parameters used for generating the diagram, including:

• Neutral axis angle

• Axial load

• Maximum compression strain

• Maximum tension strain

• Maximum curvature

• Number of curve points

After modifying the desired parameters, click the Refresh button to update the diagram.

Toolbar Options

The Moment Curvature toolbar provides the following options:

Curve Type Drop-Down List

Select the type of curve to be displayed. Available options include:

• Moment vs Curvature

• Compressive Steel Force vs Curvature

• Concrete Force vs Curvature

• Maximum Steel Strain vs Curvature

• Maximum Concrete Strain vs Curvature

• Neutral Axis vs Curvature

Sign Convention Option

For the following curve types:

• Compressive Steel Force vs Curvature

• Concrete Force vs Curvature

• Maximum Steel Strain vs Curvature

• Maximum Concrete Strain vs Curvature

an additional toolbar option is available to modify the sign convention.

• Change Sign Convention Button
  Click the +ve or −ve button to treat compression as positive or negative, respectively.
  Note: Column Designer considers compression as positive by default; this option is provided for user preference in plotting moment–curvature diagrams.

Neutral Axis Reference Option

For the Neutral Axis vs Curvature diagram, an additional toolbar option allows selection of the reference point for neutral axis depth:

• Neutral Axis Depth Button

  • YNA: Measures neutral axis depth from the centroid of the section

  • NA: Measures neutral axis depth from the top of the section

Output and Reporting Tools

• Tabulated Output Button
  Displays the numerical data corresponding to the currently displayed curve. The data can be:

  • Exported to Excel using the Export button

  • Copied to the clipboard using the Copy button

• Add to Report Button
  Adds the moment–curvature diagram to the detailed report.

• Curve Details Button
  Opens the Curve Details form, which displays key parameters such as:

  • Cross-section angle

  • Axial load capacity

  • Initial stiffness

  • Ductility ratio

Note

Moment–curvature curves are primarily intended for:

• Reinforced concrete sections, and

• Composite sections (concrete sections with embedded steel)

Use the Results Menu → Moment Curvature → Moment Curvature Details button or
Project Explorer → Columns → Results → Moment Curvature → Moment Curvature Details
to view detailed moment–curvature information at multiple points along the curve.

Overview

The working area is divided into two sections with associated toolbars:

• Left Section – Moment Curvature Curve

• Right Section – Stress/Strain Contour

As the cursor is moved along points on the moment–curvature curve, the following information is displayed in the context-sensitive grid:

• Point status

• Force components

• Moment and curvature values

• Strain values

• Neutral axis depth

• Stiffness values

Simultaneously, the neutral axis location and corresponding stress/strain contours are displayed in the stress/strain contour section.

Moment Curvature Toolbar Options

Curve Type Drop-Down List

Use this drop-down list to select the type of curve to be displayed. Available options include:

• Moment vs Curvature

• Compressive Steel Force vs Curvature

• Concrete Force vs Curvature

• Maximum Steel Strain vs Curvature

• Maximum Concrete Strain vs Curvature

• Neutral Axis vs Curvature

Sign Convention Option

For the following curve types:

• Compressive Steel Force vs Curvature

• Concrete Force vs Curvature

• Maximum Steel Strain vs Curvature

• Maximum Concrete Strain vs Curvature

an additional toolbar option is available to change the sign convention.

• Change Sign Convention Button
  Click the +ve or −ve button to treat compression as positive or negative, respectively.

Note: Column Designer considers compression as positive by default. This option is provided to allow flexibility in graphical interpretation.

Neutral Axis Reference Option

For the Neutral Axis vs Curvature diagram, an additional toolbar option allows the reference point for neutral axis depth to be selected:

• Neutral Axis Depth Button

  • YNA: Neutral axis depth measured from the centroid of the section

  • NA: Neutral axis depth measured from the top of the section

Axial Load and Neutral Axis Controls

• Value of Pu Edit Box
  Displays the axial load level for the currently displayed curve.
  Enter the desired axial load (Pu) and click Refresh.

• Angle Drop-Down List
  Displays the neutral axis angle for the currently displayed curve.
  Select the desired angle and click Refresh.

• Refresh Button
  Updates the displayed curve after changes to axial load or neutral axis angle.

Output and Reporting Tools

• Tabulated Output Button
  Displays numerical values for the curve currently shown.
  The output can be:

  • Exported to Excel using the Export button

  • Copied to the clipboard using the Copy button

• Add to Report Button
  Adds the moment–curvature details to the detailed report.

• Curve Details Button
  Opens the Curve Details form, displaying:

  • Cross-section angle

  • Axial load capacity

  • Initial stiffness

  • Ductility ratio

Stress/Strain Contour Toolbar Options

The toolbar associated with the stress/strain contour section includes:

• 2D Button
  Displays the stress/strain contour in 2D view.

• 3D Button
  Displays the stress/strain contour in 3D view.

• Type of Contour Drop-Down List
  Select the contour type to display:

  • Concrete stress

  • Bar stress

  • Concrete strain

  • Bar strain

Figure: Moment Curvature Details View

Use the Results Menu → Moment Curvature → Max Curvature Plot button or
Project Explorer → Columns → Results → Moment Curvature → Max Curvature Plot
to view the Maximum Curvature Plot.

Clicking this button activates the Diagram Grid in the context-sensitive area, where various parameters controlling the maximum curvature plot can be adjusted, including:

• Maximum compression strain

• Maximum tension strain

• Maximum curvature

• Maximum curvature factor

• Number of curve points

After making the required changes in the Diagram Grid, click the Refresh button to update the plots.

Display Layout

The working area is divided into three sections, each with its own associated toolbar. These sections are described below.

Maximum Curvature Surface

This section displays the Maximum Curvature Surface as a color-coded 3D plot.

• The three governing parameters of the surface are:

  • Axial load

  • Curvature about local 2-axis

  • Curvature about local 3-axis

• Axial load is plotted along the vertical axis, while the two curvatures are plotted along orthogonal horizontal axes.

• The surface provides an overall visualization of how the maximum curvature capacity varies with axial load and bending direction for the selected column section.

• A color-coded legend is displayed at the extreme right of the section to assist in interpreting axial load values.

Axial Load vs Curvature Curve

This section displays the variation of axial load with curvature for a selected neutral axis angle.

Associated Toolbar Options

• Angle Drop-Down List
  Displays the neutral axis angle for the currently displayed curve.
  Select a different neutral axis angle to update the curve automatically.
  Hover the cursor over the curve to read values at any point.

• Tabulated Output Button
  Displays the numerical data for the currently displayed curve.
  The data can be:

  • Exported to Excel using the Export button

  • Copied to the clipboard using the Copy button

• Add to Report Button
  Adds the axial load versus curvature diagram to the detailed report.

Curvature–Curvature Curve

This section shows the variation of curvature about the two principal axes for a specified axial load, considering multiple neutral axis orientations.

Associated Toolbar Options

• Value of Pu Edit Box
  Displays the axial load level corresponding to the currently displayed curvature–curvature curve.
  Enter a new axial load value (Pu) to update the curve automatically.

• Tabulated Output Button
  Displays the numerical values for the displayed curvature–curvature curve.
  The output can be:

  • Exported to Excel using the Export button

  • Copied to the clipboard using the Copy button

• Add to Report Button
  Adds the curvature–curvature diagram to the detailed report.

Figure: Maximum Curvature Plot

Use the Results Menu → Moment Curvature → Axial Load Strain button or
Project Explorer → Columns → Results → Moment Curvature → Axial Load Strain
to plot the Axial Load vs Strain relationship for the selected column section.

Clicking this button activates the Diagram Grid in the context-sensitive area, where various parameters controlling the axial load–strain diagram can be specified, including:

• Maximum compressive strain

• Maximum tensile strain

• Number of curve points

After making the necessary changes in the Diagram Grid, click the Refresh button to update the diagram.

Interpretation of Axial Load–Strain Diagram

The Axial Load–Strain plot illustrates the variation of axial load capacity with respect to axial strain in the column section. This relationship provides valuable insight into:

• Axial stiffness characteristics of the section

• Compression and tension capacity limits

• Transition between elastic and inelastic axial behavior

• Ductility characteristics under axial loading

The curve is a fundamental section property and is independent of member length or framing conditions.

Associated Toolbar Options

The following toolbar option is available for the Axial Load–Strain plot:

• Add to Report Button
  Click this button to add the Axial Load vs Strain diagram to the detailed report.

Figure: Axial Load – Strain diagram

This section describes the procedure for viewing and printing reports in Column Designer.
The report automatically takes into consideration the currently selected design code and updates the reported results accordingly. Therefore, while the content of the report may differ for various design codes, the procedure for viewing and printing the report remains unchanged.

Reports can be viewed by selecting any of the available report options under:

• Project Explorer → Report, or

• Results Menu → Reports

The following three types of reports are available:

• Column Summary

• Simple Report

• Detailed Report

Use the Results Menu → Reports → Column Summary button or
Project Explorer → Report → Column Summary
to access the Column Summary Form.

The Column Summary Form (Figure 6.1) provides a concise overview of critical information for all columns in the Project File, including:

• Governing load combination

• Rebar configuration

• Rebar ratio

• Corresponding demand-to-capacity (D/C) ratio

This summary allows the user to quickly identify controlling cases and assess the adequacy of columns within the project.

Figure: Column Summary Form

Use the Results Menu → Reports → Simple Report button or
Project Explorer → Report → Simple Report
to generate a one-page report for each column in the Project File.

The Simple Report provides a concise, printable summary of essential column design information, including:

• Section geometric properties

• Material properties

• Rebar configuration and details

• Governing load combination

• P–M interaction diagram

• M–M interaction diagram

This report is intended for quick review, documentation, and sharing of column design results without the level of detail provided in the Detailed Report.

Simple Report Toolbar Options

The following options are available in the context-sensitive toolbar of the Simple Report:

• Zoom Level Drop-Down List
  Select a predefined zoom level to view the report at the desired scale.

• Zoom In Button
  Zoom in to enlarge the report view.

• Zoom Out Button
  Zoom out to reduce the report view.

• Reset and Refresh View Button
  Restore the original default display of the report.

• Print Button
  Print the currently displayed Simple Report.

Figure: Simple One Page Report View

Use the Results Menu → Reports → Detailed Report button or
Project Explorer → Report → Detailed Report
to access the Detailed Report for all columns in the Project File.

The Detailed Report provides a comprehensive, code-aware documentation of the column design and analysis results. The report content automatically adapts to the currently selected design code.

Contents of the Detailed Report

The Detailed Report includes the following information for each column:

• Project Information

• Column section diagrams

• Material properties

• Stress–strain model parameters

• Rebar properties and layouts

• Section geometric properties

• Framing information (for slender columns)

• Loading details

• Design checks and capacity results

This report is intended for formal design documentation, peer review, and regulatory submission.

Detailed Report Toolbar Options

The following options are available in the context-sensitive toolbar of the Detailed Report:

• Zoom Level Drop-Down List
  Select a predefined zoom level to view the report at the desired scale.

• Zoom In Button
  Zoom in to enlarge the report view.

• Zoom Out Button
  Zoom out to reduce the report view.

• Reset and Refresh View Button
  Restore the original default display of the report.

• Print Button
  Print the Detailed Report

Figure: Detailed Report

Additional graphics can be included in the Detailed Report at any time before printing.

To add graphics:

• Click the Add to Report button available in the context-sensitive toolbar of any diagram under the Results Menu (e.g., interaction diagrams, stress contours, moment-curvature plots).

All added graphics will automatically appear in the Detailed Report in the order they are added.

Both the Simple Report and the Detailed Report can be printed by clicking the Print button in their respective toolbars.

To save a report:

• Print the report to PDF format using a PDF printer.

This allows the reports to be archived, shared electronically, or submitted for review.