Universal joint definition

@EDGE_NAME {EdgeName}
@COMMENTS {CommentText}


  1. A universal joint is a constraint element that allows the relative rotation of two bodies about two specific axes, see fig. 1. The universal joint is associated with an edge, EdgeName. Vertices Vertex0Name and Vertex1Name are associated with this edge. Find more information about: the representation of multibody systems, and the formulation of constraints in multibody systems.
  2. Figure 1. Configuration of a universal joint.
  3. The geometry of the universal joint is inherited from edge, EdgeName, which must have two associated triads, Triad0Name and Triad1Name. The two relative rotation of the bodies are allowed along the third axes of triads Triad0Name and Triad1Name, which are attached to body Vertex0 and Vertex1, respectively.
  4. The relative rotation elements, Rvr0Name and Rvr1Name, give access to relative rotations, Φ0 and Φ1, at the universal joint. Rotation Φ0 corresponds to the rotation of the cruciform with respect to body Body0Name, whereas rotation Φ1 corresponds to the rotation of the cruciform with respect to body Body1Name.
  5. It is possible to attach comments to the definition of the object; these comments have no effect on its definition.

Graphical parameters

  1. The appearance of the universal joint during the visualization phase of the analysis can be controlled by associating visualization parameters, VizPrmName, to the element. The following representations are valid for universal joints: RprType = SYMBOL or TRIAD. The SYMBOL representation depicts the universal joint as a symbol centered at the point that defined the element. The TRIAD representation depicts the universal joint as two triads sharing a common origin and oriented according to the configuration of the two bodies connected to the joint. Default value: SYMBOL. No vector fields can be associated with universal joints.


  1. Sensors can be defined to extract information about universal joints. The following SensorType and associated FrameName specifications are allowed for universal joints: ACCELERATIONS_0, ACCELERATIONS_1, DISPLACEMENTS_0, DISPLACEMENTS_1, CONFIGURATION_0, CONFIGURATION_1, VELOCITIES_0, and VELOCITIES_1. (Default value: DISPLACEMENTS_0).
  2. No u value or v value are accepted for universal joints.