Load Cases
For a Stationary study, you can define load cases and constraint cases. A load or constraint can be assigned to a load or constraint group, and then used conditionally.
For most load types, the load case acts as a simple multiplier, but some cases need a more detailed discussion:
A Prescribed Displacement or Prescribed Displacement/Rotation node can be assigned both a constraint group and a load group. You can use the constraint group to switch off the whole constraint. The load group acts as a multiplier to nonzero prescribed values of displacement and rotations.
When a load case multiplier is used for Thermal Expansion, the multiplier is applied not to the actual temperature, but to the difference between the temperature and the strain free reference temperature. The temperature difference, and thus the thermal strain, is proportional to the load case multiplier.
Since Thermal Expansion nodes are exclusive (only the last one given gives a contribution for a certain domain), you cannot switch between different Thermal Expansion nodes only by assigning them to different load cases.
A Spring Foundation or Thin Elastic Layer node can be assigned a constraint group, which you can use to switch it on and off. If there is also a Predeformation subnode, then you can assign a load group to that subnode. The prescribed predeformation is then multiplied by the load case multiplier. Predeformation nodes are exclusive, you cannot switch between them by assigning them to different load cases.
A Rigid Connector can be assigned both a constraint group and a load group. You can use the constraint group to switch off the prescribed displacements and rotations. The load group acts as a multiplier to nonzero prescribed values of displacement and rotations.
If you have added Applied Force or Applied Moment nodes under a Rigid Connector, you can assign individual load groups to these nodes
If you have added Applied Force or Applied Moment nodes under a Rigid Domain, you can assign individual load groups to these nodes.
For an example about how to set up expressions for controlling position and distribution of loads using load cases, see Pratt Truss Bridge: Application Library path Structural_Mechanics_Module/Civil_Engineering/pratt_truss_bridge.