Harmonic Perturbation
Use the Harmonic Perturbation subnode to specify the harmonic part of nonzero prescribed displacements, rotations, velocities, or accelerations. This node is used if the study step contains frequency response of a perturbation type.
The settings are the same as in the parent Prescribed Displacement, Prescribed Displacement, Interface, Prescribed Velocity, Prescribed Velocity, Interface, Prescribed Acceleration, Prescribed Acceleration, Interface, Prescribed Displacement/Rotation or Rigid Connector node. Only degrees of freedom selected as prescribed in the parent node can be assigned a value.
Shell Properties

Location in User Interface
Context Menus
Ribbon
Physics tab with Prescribed Displacement, Prescribed Velocity, Prescribed Acceleration, Prescribed Displacement/Rotation, or Rigid Connector node selected in the model tree: