Sticking elements are devoted to stick non compatibles meshes toegether.

the interaction is built as a master-slave relations where each node of a slave mesh is linked to the nodes of the element of the master mesh in which the node projection is inside (or slightly outside according to a tolerance).

Two method could be used to fix the slave node inside the master element : * a penalty method * constrains applied through lagrange multipliers (not yet implemented)

Sticking Elements using penalty method consist in creating a spring between the slave node and the current position of the projection of the initial slave node position inside the master element.

The stiffness of the spring is the penalty parameter and can be modulated by the size of the elements linked to the slave element throug a mecanism similar to the “Contact Area”.

Another methodology is to impose the relation between the slave node (current) position and the current position of the projection of the initial position of the slave node inside the master element through linear constraints imposed by Lagrange multipliers. This methodology has the advantage that it does not need to calibrate a penalty coefficient, but add unknowns to the problem (DIM Lagrange Multipliers by sticking element) and need to use a solver that allows pivoting (DSS does).

This methodology is not currently availaible in Metafor, even if only the element generation has to be defined in a new specific interaction.