Constraints
Constraints define kinematic constraints on a node's degrees of freedom.
Restriction: Only available in Abaqus, LS-DYNA, and Radioss.
Abaqus Cards
| Card | Description |
|---|---|
| *COUPLING | Coupling constraint between a part and a reference node or a reference node set. Reference node sets can have more than one node. More than one reference node in a set requires the influence radius option. |
| *KINEMATIC | To be used along with *COUPLING for kinematic constraints that may include translational and/or rotation degrees of freedom. Provides a rigid constraint between independent node and dependent nodes or surface. |
| *DISTRIBUTING | To be used with *COUPLING that may include translational and/or rotational degrees of freedom. Provides a distributed connection between dependent node and independent nodes or surface based on a weighing factor. |
Additional options are available in the Entity Editor for kinematic and distributing coupling constraints:
- Influence Radius
- Radius within which the nodes are connected to the reference node
- Orientation
- Local coordinate system for the constraint DOF
- Alpha
- Thermal expansion coefficient
- Coupling
- Continuum or Structural for rotational and translational DOFs
- Weighting method
- Uniform/Linear/Quadratic/Cubic weighing methods for distribution
- Distribution Type
- Uniform value or non-uniform values at distribution nodes
- Free nodes
- Treatment of free nodes, such as remove, error, or allow
LS-DYNA Cards
- *CONSTRAINED_INTERPOLATION_SPOTWELD
- *CONSTRAINED_JOINT_STIFFNESS_(OPTIONS)
Radioss Cards
- /MERGE/RBODY