A. To specify a nonlinear analysis
To instruct the program to perform a static, geometric nonlinear analysis of the structure, use the following procedure.
The following limitations should be noted regarding static, geometrically nonlinear analyses:
- Large rotations in one step should be avoided by using more steps.
- Very large displacements, unstable structures, and/or post-buckling should be avoided.
- Geometrically nonlinear only. No tension/compression or contact is considered. No yield, plastic moment hinges or bilinear behavior is considered.
- Solids cannot be used for this analysis method.
- Temperature loads are not supported for geometric nonlinear analysis.
-
Either:
or
on the Analysis and Design ribbon tab, select the Analysis Commands tool in the Analysis Data group
- Select the Nonlinear Analysis tab.
- (Optional)
Specify the nonlinear analysis parameters as necessary:
- Type a absolute displacement limit for the first analysis step in the ARC field.
- Type the maximum number of Iterations to use to achieve equilibrium in the deform position within the specified tolerance value.
- Type the Tolerance to use for achieving convergence between two sequential iterations.
- Type the number of Load Steps to use for applying load in stages.
- Type frequency of Rebuild Steps of the tangent K matrix.
- Check the KG option to add the geometric stiffness to the stiffness matrix.
- (Optional) Check the Set Displacement Limit option to specify a target displacement:
- Select the Print Option you want to use.
- Click Add. The perform nonlinear analysis command is added to the input file.