Defining Convergence Criteria in StressCheck

The Convergence Criteria tab in the Results dialog is used for defining convergence criteria records that will be used in the context of the Solve dialog’s “Converge:” dropdown. These convergence criteria records identify extraction operations which will be performed at the completion of each finite element solution in order to test whether the solution is of sufficient quality to be used as the basis for engineering decisions. Each individual convergence criteria record is composed of the name of one or more extraction setting records and a corresponding numeric value which represents the % level of error considered acceptable for the given extraction.

Specifying the Convergence Criteria Name and Title

First, a convergence criteria name must be specified to be available under the “Converge:” dropdown in the Solve dialog. Optionally, a title may be provided to describe the convergence criteria record.

Specifying the Extraction Setting Name(s) and Error Criteria %(s)

In order to define a convergence criteria record, at least one Results extraction setting name must be available to select from the Name/Type list. Available Results extraction setting names are located in the Settings pane of the Results dialog tabs (Figure 2). Note: to store a new Results extraction setting representing the extraction defined in the current Results tab and for the selected object(s), select the Name combo-box within the Settings pane, type in a name, and click the Save button.

For an example of defining Results extraction settings, refer to StressCheck Tutorial: Defining Solution and Extraction Settings for Parametric Models.

In the Convergence Criteria tab of the Results dialog, select one or more Results extraction setting names from the Name/Type list, and enter the acceptable % error in the Criteria column (Figure 3):

Saving/Updating Convergence Criteria Records

Click the Accept button to save the convergence criteria record. The convergence criteria record will appear in the Name/Title list. A convergence criteria record can be updated at any time by selecting the record from the Name/Title list, making the required changes, and then clicking the Replace button. Note: Plot extraction settings are not applicable to error criteria.

Deleting/Purging Convergence Criteria Records

A convergence criteria record can be deleted at any time by selecting the record from the Name/Title list, and then clicking the Delete button. To delete all convergence criteria records, click the Purge button.

Selecting Convergence Criteria in the Solver Options

Once a convergence criteria record is defined, it may be activated by selecting it from the “Converge:” combo-box in the Solve dialog before clicking the Solve button (Figure 4). The convergence criteria will be checked after each run, and the solver will terminate if all convergence criteria have been met.

For an example of defining and using convergence criteria, refer to StressCheck Tutorial: Setting Up Solution Convergence Criteria.