Creo Simulate > Modeling Structure and Thermal Problems > Idealizations > Shells > Midsurface Shells > Before You Define a Shell Model > Unopposed Surfaces
Unopposed Surfaces
For Creo Simulate to create a complete shell model, you need to make sure all the surfaces you pair have an opposing surface. Unopposed surfaces can be the result of omitting a surface or surface region from a pair, or they can occur because of slight geometrical differences between surfaces that make up a pair.
You can use any of the following approaches to resolve problems due to unopposed surfaces:
If the unopposed surface is a separate feature, such as a round, you can suppress the feature.
You can use or remove unopposed surfaces during analysis. Select or clear the Remove Unopposed Surfaces check box on the FEM Mesh Settings dialog box in FEM mode or the AutoGEM Settings dialog box in native mode. If you remove these surfaces, Creo Simulateomits the unopposed surfaces from your model, and your model may have gaps. To understand how the midsurface compression of a part may differ depending upon whether you use or ignore an unopposed surface, see Example: Part with Unopposed Surfaces.
You can add an opposing surface to the model.
Return to To Test Shell Compression