Before You Define a Shell Model
Before you define your part as a shell model, be sure you have all the geometry you need already in place. Following are several factors you should be aware of when working with shell models:
• Regions—If you plan to use loads or constraints for surface regions, be aware that adding a region invalidates any prior shell definitions for that surface. Therefore, be sure to add all regions and parent surfaces before starting the shell model definition process. As an alternative, you can redefine shell definitions after you add the region. For more information, see
Surface Region.
• Properties—You can assign shells to faces, regions, or datum surfaces, and to surfaces that will be compressed. The assigned shells can then reference shell properties you define. You can also define a shell property that is not assigned to any entity. For more information, see
About Shell Properties.
• Complex Models—Simplify your model as much as possible before defining it as a shell model. Keep your model's geometry symmetric whenever possible.
Be sure to suppress any features that have no bearing on the analysis of the part. You can start by identifying areas of the model that have minimal significance in terms of carrying the load. In those areas, suppress features that serve cosmetic purposes only. Feature suppression reduces the following:
◦ the amount of time required to define surface pairs. Also, you can sometimes reduce the amount of complex geometry you may need to add in order to accommodate your pairing scheme.
◦ the time required to analyze the model by reducing the number of calculations the engine needs to complete
When determining which features to suppress, weigh the benefits of suppressing the feature against the reduction in model accuracy.