Boundary conditions are used to prescribe values of basic solution variables, for example, displacements and rotations in stress/displacement analysis. The following boundary conditions are available in the Nonlinear Structural Analysis workbench:

Creating Displacement Boundary Conditions: Defines the time history of displacement degrees of freedom on a geometry selection.

Creating Clamp Boundary Conditions: Fully constrains a geometry selection in all directions.

Importing Restraints: Imports a restraint definition from GPS into your analysis.

Creating Velocity Boundary Conditions: Defines the velocity for a geometry selection.

Creating Acceleration Boundary Conditions: Defines the acceleration for a geometry selection.

Creating Submodel Boundary Conditions: Drives the boundaries of the submodel with time-dependent variables that were saved during the analysis of the global model.

Creating Base Motion Boundary Conditions: Specifies the motion of nodes in a steady-state dynamic (mode-based or subspace-based) step. The base motion can be acceleration, velocity, or displacement.

You apply environmental actions, such as boundary conditions, to supports (geometrical features) on your model. The supports that are available include points/vertices, curves/edges, surfaces/faces, or volumes/parts. In addition, point, line, or surface groups that were created from a mesh part are also valid supports. You can either select the support and then set the boundary condition specifications or set the boundary condition specifications and then select the support. Table 9–1 summarizes the supports to which each type of boundary condition can be applied.

Table 9–1 Supports for boundary conditions.

Boundary Condition	Point, Vertex, or Point Group	Curve, Edge, or Line Group	Surface, Face, or Surface Group	Volume, Part, or Body	Other Supports
Displacement					GPS User-defined Restraint, GPS Rigid Body Constraint, or GPS Virtual Part
Clamp					GPS Clamp, GPS Rigid Body Constraint, or GPS Virtual Part
Velocity
Acceleration
Submodel
Base Motion					Clamp or displacement BC specified in the previous Frequency step