Solution Settings

SimSolid employs a proprietary adaptive technology to automatically refine the solution in the areas where it is necessary to achieve the highest accuracy. Multiple solution passes are performed and with each pass, accuracy measures are created, and equations are enriched locally as required. The only settings specified manually are the maximum number of solution passes along with a small set of optional settings.

Settings can be applied globally to the entire assembly or locally to individual groups of parts. This allows you to first determine the overall system response, then quickly drill-in to specific areas of interest.

The settings are specified independently for each analysis. This provides a convenient method to do analysis comparison and solution convergence studies.

To adjust settings, either double-click or use right mouse button to select the Edit menu. Select one of three adaption objectives.

Global: Best for general load path prediction, modes and/or thermal analysis. Uses 3 adaptive passes and Adapt to thin solids. Refinement level is set to Standard. Only uses global adaption. Typically, the fastest solution method.
Global + Local: Best for stress calculation with more precision. Uses 4 adaptive passes, Adapt to features, Adapt to thin solids. Automatically creates local group for the parts & segregates based on its relative volume. Hence, can be used for both global and local adaptations. Refinement level is set to Standard.
Custom: This is the most general objective. All controls can be individually set. To improve the accuracy over the entire assembly, increase the number of adaptive solution passes. This is a primary control to increase solution refinement. Rarely needs to be set higher than 6. Use part local adaption to refine further.

Individual Setting Controls

The following individual setting controls are available:

Adapt to features – Uses special logic that has more aggressive adaptivity for stress gradient areas at local features. Applies only to structural linear and nonlinear statics. This is not used in modal or thermal analyses.
Adapt to thin solids – provides special functions for a more accurate representation in thin curved solid sections. A best practice is to use this locally on a part-by-part basis.
Refinement level – increases the refinement level locally for a group of parts. Three levels are possible – Standard, Increased, and High.
Important: Solution settings define a strategy of solution adaptation and are applied at the scale of the selected part group.
Global solution settings define the solution refinement strategy on the whole assembly assuming that accuracy requirements are approximately equal on all parts. Global solution settings scale is the size of the whole assembly, which can be activated by opting for Global in the Solution settings window. Local solutions setting define the solution refinement strategy on a part or group of parts. The scale of the settings is the size of the parts in the group, which can be activated in two ways. One is by selecting Global + Local solution settings, where the parts are automatically grouped by its relative volume. The other way is by selecting Custom solution settings, where the local groups can be created either manually by choosing New group or automatically by selecting Group by part volume.

Part volume grouping is automatically done based on the total volume of the assembly. The parts that account for the 10 percent of the total volume are grouped together. For example, the top 10 percent go into group 1, 10-20 percent in group 2 and so on.

The same solution settings applied to the whole assembly or to a specific part will have different effects on the accuracy. The local settings are always more aggressive on the given set of parts because the scale is smaller. This facilitates the ability to do global-local analysis and to focus the adaptive refinement on areas of interest.

Note: Solution settings associated with each analysis are copied when an analysis or design study is copied. When a new design study is created by importing new geometry, local part groups created under Custom solution settings remain if at least one part in the groups is the same as in the baseline design study. All new parts are added to Group 1. If the local part groups were created using Global + Local solution settings, it will automatically segregate the parts in groups based on their relative volume irrespective to the change in design.

Solution Settings Usage Road Map

The recommended usage for Solution settings is as follows:

Find overall system load path

Use global adaptation.

Considerations for local stress studies

Use local part groups. This can be done in two methods as explained above: Global + Local and Custom.

Remember: Part group settings are done at the part group local scale.

Examine overall solution convergence

Increase the number of adaptive passes and rerun the model. Number of passes can be set between 3 and 9, but this value is rarely set above 6. This can be done using Custom solution settings.

Considerations for thin curved solids

Select the Adapt to thin solids check box. This is best done on a part-by-part basis using local part groups.

Apply Global Solution Settings – Apply solution settings to the entire assembly.
Apply Local Solution Settings – Apply solution settings to groups of parts in the assembly.
Apply Global Fatigue Solution Settings – Apply fatigue solution settings to the entire assembly.
Apply Local Fatigue Solution Settings – Apply fatigue solution settings to a group of parts in the assembly.