FIXROT,[Stiff]

Command to fix rotations of solid rotation and in-plane shell rotations. This command will attempt to fix rotations by using the equivalent of the D command to fix rotations that shouldn't be free. However, shells faces that are not parallel to a dimension of global coordinate system cannot be fixed in this way. Therefore, this command will also add a spring to each node on a shells face that has stiffness parallel to the normal of the shells face. The user can control the stiffness of this spring by the stiff parameter of the command.

Stiff – Stiffness of springs added to shells to remove the singularities. (default stiffness 100)