Mechanism Constraints

Mechanism Constraint entities define kinematical constraints on a body at a specified node or point location.

Mechanism Constraints are created and organized in the Mechanism Browser.

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
Local coordinate system for the constraint DOF
Thermal expansion coefficient
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