The response in a linear analysis step is the linear perturbation response about the base state. The base state is the current state of the model at the end of the last general analysis step prior to the linear perturbation step. If the first step of an analysis is a perturbation step, the base state is determined from the initial conditions. For more information, see “Linear perturbation analysis steps” in “General and linear perturbation procedures,” Section 6.1.2 of the ABAQUS Analysis User's Manual.
When you configure a static, linear perturbation procedure, the step editor displays the Basic and Other tabs. You use these tabbed pages to describe the step and to enter equation solver preferences.
To configure a static, linear perturbation procedure:
In the Edit Step dialog box, display the Basic tabbed page.
(For information on displaying the Edit Step dialog box, see “Creating a step,” Section 14.9.2, or “Editing a step,” Section 14.9.3.)
In the Description field, enter a short description of what occurs during this analysis step. ABAQUS/Standard stores the text that you enter in the output database, and the text is displayed in the state block by the Visualization module.
Display the Other tabbed page.
Select the Equation Solver Method option of your choice:
Select Direct to use the default direct sparse solver.
Select Iterative to use the domain decomposition iterative linear equation solver. For more information, see “Iterative linear equation solver,” Section 6.1.5 of the ABAQUS Analysis User's Manual.
Select the Matrix storage option of your choice:
Select Use solver default to allow ABAQUS/Standard to decide whether a symmetric or unsymmetric matrix storage and solution scheme is needed.
Select Unsymmetric to restrict ABAQUS/Standard to the unsymmetric storage and solution scheme.
Select Symmetric to restrict ABAQUS/Standard to the symmetric storage and solution scheme.
Once you have finished configuring settings for the static, linear perturbation step, click OK to close the Edit Step dialog box.