Columns

If there are any results displayed, switch them off by clicking the button on the toolbar. Click the button to set the axonometric view.

For a better view, select the Wireframe Model option that you can access by clicking the button on the toolbar.

Selecting Display of 'Wireframe Model'

To select the two columns, draw a window from right to left across them. Do not capture any other members within.

Selecting Columns

Double-click one of the selected columns to open the 'Edit Member' dialog box. On the first tab, the 'Design properties' are enabled so that additional tabs are available to control the settings.

Design Properties Activated for Columns

Effective Lengths

Select the Design Types tab.

Creating New Type of Effective Length

For the columns, the method for uniform members is to be used. Next to the 'Effective lengths' line, click the button to create a new length type. The 'New Effective Lengths' dialog box opens.

Main Settings for Effective Lengths

In the 'Consider effective lengths for' area, clear the Flexural buckling about y/u (major axis) check box. It is not required to verify flexural buckling in the plane of the frame because imperfections were defined in that direction (see Part 1).

To check the column axes, use the button in bottom part of the right area. The real view of the model is displayed.

Select the Nodal Supports & Effective Lengths tab next.

Nodal Supports and Effective Lengths

Supports are set at both member ends by default. The preset type is laterally fixed with a torsional restraint about the longitudinal axis ("forked"), yet free to warp.

In the 'Effective Length Factors' area, the factors are set as 1.0. They represent a hinged-hinged model concerning buckling. One might consider the elasticity of the column heads by increasing the buckling length factors, but assuming fixed supports is adequate for the tutorial.

Options to Adjust Effective Lengths

Click OK to close the dialog box and return to the 'Edit Members' dialog box.

Effective Lengths of Type "1" for Columns

Design Configuration

Finally, select the Design Configurations tab. The 'Default' ultimate configuration is preset (see the 'Main' Settings of Ultimate Configuration image). It would be possible to define a new configuration and apply it only to the columns, but this is not required for the tutorial.

Design Configuration for Columns

Click OK to assign the effective lengths and close the 'Edit Members' dialog box.