Creating Composed Joints

You can create a composed joint to customize the degrees of freedom to control for a joint.

This task shows you how to:

See Also
About Joints

Specify the Definition Properties

  1. From the Mechanism section of the action bar, click Joint .
  2. In the dialog box, select Composed from the list of joint types.
  3. In the Definition section of the dialog box, select the two markers between which to create the joint.
    1. Click the From marker box and select a marker in the work area.
    2. Click the To marker box and select a marker in the work area.

    Tips:
    • To edit the selected markers, click and select Edit. The Markers dialog box opens.
    • To modify your selection, click and select Clear selection. You can select another marker in the work area or in the tree.

  4. Optional: To create the joint using a new marker:
    1. Click Create a new marker .

      Tip: You can also click and select Create a new marker.

    2. In the tree, select the body on which to create the marker.
    3. In the Markers dialog box, define the marker.

      For more information, see Creating Markers.

    The new marker appears in the tree and the name of the marker appears in the box.
  5. Select the x, y, or z-axis as the translation axis.
  6. Optional: Select the x, y, or z-axis as the first, second, or third rotation axis.
  7. Optional: In the States table, specify values to control the joint motion. To do so, in each row:
    1. Select the Lower limit check box to enable a lower bound in a specific direction.
    2. Select the Value check box to enable an initial value.
    3. Select the Upper limit check box to enable an upper bound in a specific direction.

    Notes:
    • Each row corresponds to a translation or rotation degree of freedom. The number of rows depend on the joint type.
    • If the lower and upper limits are not applicable, no check box appears in the corresponding row or column.

Specify the Conic Properties

  1. Select the Conic limit check box to apply an upper bound on the conic opening angle of rotations.
  2. Specify the maximum angle value in degrees.

Specify the Limit Enforcement Properties

The Limit Enforcement section appears if you define the joint Lower limit, Upper limit or Value in the States table.

  1. In the Limit Enforcement section of the dialog box, select one of the following methods to enforce upper or lower limits during the simulation.
    OptionDescription
    Restitution Specifies the relative kinetic energy loss when reaching the limit.
    Stiffness damping Specifies the stiffness and damping applied when exceeding the limit.

    Note: Depending on the joint type, limit enforcement options are available for each rotation or translation state, and for every upper or lower limit enabled.

  2. Optional: Select Root handling to resolve the exact time when the limit or limits are reached.
  3. If you select Restitution, specify a restitution coefficient.
  4. If you select Damping, specify a value for the stiffness and the damping.
  5. In the tree, the joint appears under the Joints node.

Edit the Joint

  1. To edit a joint, in the tree, do one of the following:
    • Double-click a joint.
    • Right-click a joint and select Definition from the object menu.
  2. In the dialog box, edit the joint parameters.
  3. Click OK.

    Note: To modify the general properties or graphical properties of the element, right-click the element in the tree and select Properties. For more information, see Displaying Properties.