Tightening Join

Join element allows connecting a node and a face of an element.

Mesh visualization:

The relations are obtains in the following way:

1. Compute the projection of the slave node (N1) on the surface defined by n-1 master nodes.
2. Interpolate the displacement of the projected point (P) using the shape function of the face defined by the master nodes.
3. Link the displacement of the slave node (N1) to the displacement of the projected point (P) using rigid-body equations, except for the translation in the direction of the tightening given by the property.
4. Impose a minimum overlap in the direction given by the property between the slave node (N1) and the projected point (P).

The projected point (P) is a conceptual point, that means it is never created. The displacement of this point is always expressed in terms of displacement of the master nodes through interpolation.

Tightening elements generate a two-steps computation:

1. Submit a tightening force,
2. Impose a minimum overlap equal to the overlap obtained in the first step.