Define a rigid link in a frame structure

A rigid link is used to model rigid elements of elastic structures (definition of a rigid body in a structure). Displacements and rotations defined for a rigid link can be limited to certain selected degrees of freedom.

To learn more about rules applied during automatic conversion of frame assembly, see the Automatic Model Conversion Help topic.

You need at least two nodes to define a rigid link, one parent node and one or more child nodes. Parent node passes its parameters (degrees of freedom) down to child nodes during simulation.

Note:

• If a node is a child node of an existing rigid link, you cannot define it as a node in the rigid link.
• You cannot add a rigid type constraint to the child node. You can only add elastic type of constraint. Use Custom Constraint command to add a constraint with elasticity.
• You cannot define a child node as a node compatible with other nodes. Parent nodes can have compatibility defined with other nodes.
• You cannot use a rotated constraint in the parent node of a rigid link for the selected degrees of freedom.
• You cannot add constraints to child nodes of rigid link.

Rigid links are defined in the global coordinate system.

To define a new rigid link:

On the ribbon, click Frame Analysis tab Connections panel Rigid Link Select the parent node. Select one or more child nodes. Note: You can define a node as a child node only in one rigid link. Specify the blocked displacement. X - axis: When selected, the displacement in the X direction in child nodes is blocked in the rigid link. Y - axis: When selected, the displacement in the Y direction in child nodes is blocked in the rigid link. Z - axis: When selected, the displacement in the Z direction in child nodes is blocked in the rigid link. Specify the blocked rotation: X - axis: When selected, the rotation about the X axis in child nodes is blocked in the rigid link. Y - axis: When selected, the rotation about the Y axis in child nodes is blocked in the rigid link. Z - axis: When selected, the rotation about the Z axis in child nodes is blocked in the rigid link. Click OK to create a rigid link.

Note: Unblocked degrees of freedom apply only to the child nodes of a rigid link.

To remove a rigid link, select the rigid link in the browser, right-click, and select Delete.