Fallback Conditions to Contact Regions
Certain boundary conditions may act as fallback conditions to a contact region, or any pair region, if their selection overlaps with the source and destination boundaries. The Layered Shell interface does not support any fallback conditions. When a boundary condition is considered as a fallback, the condition is only active for regions that are not in contact.
In the Solid Mechanics; Solid Mechanics, Explicit Dynamics; and Multibody Dynamics interface, boundary conditions recognized as fallback conditions if their selection intersects any source and destination boundary include:
In the Shell and Membrane interfaces, following boundary conditions recognized as fallback conditions include:
To enable the fallback condition in these nodes, change the Allowed region to Fallback and nonpair regions in the Applicable Pair Regions section of settings window of the node. To display the Applicable Pair Regions section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog.
The most common case when a fallback condition is used is when there is a pressure load acting on the part of the boundary that is currently not in contact. In this case you would add a Boundary Load or Face Load with a selection that intersects with the source and destination boundaries.