Creating Rigid Links (FEM mode)
When you click
Refine Model >
Rigid Link command, the
Rigid Link Definition dialog box appears. To fully define a rigid link, you must name it and specify the following in the
Rigid Link Definition dialog box:
• Type—Select one of the following types of a rigid link. The lower half of the dialog box changes depending upon the type of rigid link you select.
◦ Simple—
Creates a rigid link between references that can be a collection of any number of any type of geometric entities.
◦ Advanced—Select the geometric entity from the independent and the dependent sides.
• Independent Side—Select a point or surface in the model as a geometric reference. The independent side collector in the Rigid Link Definition dialog box displays your selection.
• World (WCS) is the default coordinate system. Retain the WCS or select a UCS (
Selected) or set the
Nodal coordinate system option in the
CSYS area for the independent side. The selected coordinate system overrides the default WCS or the displacement coordinate system that you have assigned using the
Mesh Control dialog box.
|  You cannot override the displacement coordinate system that has been earlier specified by another rigid link, load, or constraint associated with the selected reference entity. If you output to NASTRAN, conflicts between coordinate systems may occur. |
• Dependent Side—Select one or more entities of the same type. You can select points, edges, curves, or surfaces. When you select a surface on the independent side, the only reference available on the dependent side is a surface.
| You cannot constrain the dependent side of a rigid link. If you try to do so then, Creo Simulate displays a warning but goes ahead and constraints the dependent side of the rigid link. The constrained dependent side, is however ignored during the creation of the mesh. |
• As on the independent side, you can retain the default WCS or select a UCS or Nodal coordinate systems on the dependent side.
• Project to References—Use this option to create a rigid link between a point on the independent side and the projection of that point on the dependent side. This option is available only when you select a point for the independent side and edges, curves or surfaces for the dependent side. If you do not select this option, the rigid link is displayed as a hashed line, and rigid link elements are created between the independent node and all the nodes on the dependent side. Otherwise, the rigid link is displayed as a continuous line, and rigid link elements are created between the independent node and the projection node.
| Rigid links created using the Project to References option are suppressed in the native mode. |
• Degrees of Freedom—Use this option to specify the degrees of freedom for the dependent reference entity. Degrees of freedom define the ability of a node on the dependent side of the link to move in any direction in space. The node may have six degrees of freedom—three translational and three rotational.
Note that if you change references or delete a link that has already been meshed, Creo Simulate erases the mesh.
After you create your rigid link,
Creo Simulate displays two
icons on the model—one for the rigid link and another for the degrees of freedom.