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*COUPLING

Keyword type: model definition

This option is used to generate a kinematic or a distributing coupling. It must be followed by the keyword *KINEMATIC or *DISTRIBUTING.

The parameters REF NODE, SURFACE and CONSTRAINT NAME are mandatory, the parameter ORIENTATION is optional.

With REF NODE a reference node is chosen, the degrees of freedom of which are used to define the constraint. In the reference node six degrees of freedom are available: 1 to 3 for translations in the x-, y- and z- direction and 4 to 6 for rotations about the x-, y- and z- axis. For *KINEMATIC couplings the location of the reference node determines the center of the rigid motion and is therefore important. For *DISTRIBUTING couplings the motion takes place about the center of gravity of the SURFACE and the coordinates of the reference node are not relevant. However, for *DISTRIBUTING coupling the reference node should not be one of the nodes of the surface to which the constraint applies.

With SURFACE the nodes are selected to which the constraint applies (so-called coupling nodes). This surface must be face-based.

The parameter CONSTRAINT NAME is used to assign a name to the coupling condition. This name is not used so far.

Finally, with the ORIENTATION parameter one can assign a local coordinate system to the coupling constraint. Notice that this does not induce a change of coordinate system in the reference node (for this a *TRANSFORM card is needed). For distributing couplings only rectangular local systems are allowed, for kinematic couplings both rectangular and cylindrical systems are alllowed, cf. *ORIENTATION.


First line:

Example:

*COUPLING,REF NODE=200,SURFACE=SURF,CONSTRAINT NAME=C1,ORIENTATION=OR1

defines a coupling constraint with name C1 for the nodes belonging to the surface SURF. The reference node is node 200 and an orientation OR1 was applied.


Example files: coupling1.


next up previous contents
Next: *CREEP Up: Input deck format Previous: *COUPLED TEMPERATURE-DISPLACEMENT   Contents
guido dhondt 2018-12-15