Nastran reference manual : Constraints (Points, Lines, Surfaces)

MENU SEQUENCE:
Data →  Boundary Conditions → Constraints


Allows assigning prescribed displacements and rotations around global axes.
These conditions can be assigned over points, lines and surfaces, and affect nodes.
X-Constraint->Prescribed displacement along X-global axis
X-Rotation->Prescribed rotation around X-global axis
The prescribed displacements and rotations always make references to global axes.