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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 belong to 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 2017-10-08