Rigid rotation definition

@RIGID_ROTATION_DEFINITION {
@RIGID_ROTATION_NAME {RigRotName} {
@CONNECTED_TO_VERTEX {VertexName}
@FUNCTION_1D_NAME {Fun1DName}
@ANGULAR_VELOCITY { ω1, ω2, ω3}
@BODY_LIST {BodyName1, BodyName2,... BodyNameN}
@FRAME_NAME {FrameName}
@COMMENTS {CommentText}
}
}

Introduction

The concept of rigid rotation is used in static analysis. In that case, the centrifugal forces associated with the rigid rotation are computed and applied to the system in a quasi-steady manner. Rigid rotations are ignored in dynamic analysis.

NOTES

  1. The rigid rotation is defined by the components of the angular velocity vector Ω = (ω1, ω2, ω3), whichis attached to vertex VertexName.
    1. If no FrameName is defined, the components of the vector are measured in inertial frame I.
    2. If the FrameName is defined, the components of the vector are measured in the frame FrameName, that can be a fixed frame or a moving frame.
  2. The magnitude of the angular velocity vector changes in time according to 1D function, Fun1DName, of type TIME_FUNCTION.
  3. The bodies undergoing the rigid rotation are specified in the body list. They can be structural elements such as beams, or constraint elements such as revolute joints, for instance.
  4. It is possible to attach comments to the definition of the object; these comments have no effect on its definition.