Set up a Buckling Analysis

1. Click Analysis Analysis Types. The Analysis Types dialog opens.
2. Select an existing case, and then click Change analysis type. The Change Analysis Type dialog opens.
3. Select Buckling, and then click OK. The Buckling Analysis dialog opens.
4. Specify the number of required modes, the tolerance, and the maximum number of iterations for the analysis.
5. Select a method to solve the eigenproblem. Two methods are available:
   • Subspace iteration
   • Block subspace iteration.
6. If you select the Block subspace iteration method, click Parameters to define shifts.
   Note: Using shifts is useful if you want to speed up the process convergence and to shift the convergence center to the selected spectrum part. However, avoid setting an excessively small number of iterations between successive shifts. It leads to frequent reinforcement-aggregation and decomposition of the shifted stiffness matrix K_σ. These are particularly time-consuming operations, especially in the case of big structures.
7. Select Sturm check if you want to restart the calculations when skipped vibration modes are found in the structure.
8. To set up a nonlinear analysis, select either or both of the non-linearity options, and then click Parameters to specify the parameters of the nonlinear analysis.
9. Click OK to go back to the Analysis Type dialog. The analysis type is updated for the selected case.

Note: If you already selected an iterative solver in the Job Preferences, you don't need to select an iterative method. In this case, only the number of modes, the tolerance, and the number of iterations are considered.