This boundary conditions is used to apply the forces that act on a structure when it rotates around a fixed axis. The axis itself has to be fixed, but the rotational speed is allowed to vary with time (or frequency for a harmonic analysis). The user has to specify a volume on which the force acts as well as the rotational speed (in radians per second) and the axis of rotation.
The rotational speed can be either constant, or a time-dependent (or frequency-dependent respectively). The variable speed has to be given by a function or a table.
The rotational axis is defined by its direction and a point on the axis.
The user has to define an arbitrary point on the axis of rotation in the global coordinate system of the mesh.
The direction of the rotational axis is defined by three directional values in the global coordinate system. This direction vector doesn’t need to have unit length.