Nonlinear Parameters Form

Access the Nonlinear Parameters form as follows:

Click the Define menu > Analysis Cases command to display the Analysis Cases form.
Click the Add New Case button or highlight a previously defined analysis case and click the Add Copy of Case or the Modify/Show Case button to display the Analysis Case Data form.
Make one of the following selections:

Select Static from the Analysis Case Type drop-down list and select the Nonlinear or Nonlinear Staged Construction option for Analysis Type.
Select Time History from the Analysis Case Type drop-down list and the Nonlinear option for Analysis Type and the Direct Integration option for Time History Type.

Click the Nonlinear Parameters Modify/Show button on the Nonlinear Static, Nonlinear Static Staged Construction or Analysis Case - Nonlinear Direct Integration History form to display the Nonlinear Parameters form.

The Nonlinear Parameters form requires somewhat different data depending on the type of analysis.

Material Nonlinearity Parameters area. The data in this area of the form is informational only. For nonlinear modal time-history (FNA) analysis, only link-object material nonlinearity is considered. For nonlinear static and nonlinear direct-integration time-history analysis, all link- and frame-object nonlinearity is considered.

Geometric Nonlinearity Parameters area. Geometric nonlinearity is only available for nonlinear static and nonlinear direct-integration time-history analysis. See Geometric Nonlinearity Parameters for more information.
Solution Control area. The solution control parameters are different for each type of analysis. See Solution Control for more information.
Hinge Unloading Method area. This option is only available for nonlinear static analysis, and is primarily intended for pushover analysis using frame hinge properties that exhibit sharp drops in their load-carrying capacity. See Hinge Unloading Method for more information.

Click the Reset to Defaults button to restore the program default to the various options on the form.