1. But

Define the geometric elements relating to a crack, including the crack bottom and the upper and lower lips of this crack, in a 2D or 3D mesh.

The definition of the bottom of the crack can be done from entities (nodes or cells) or from groups of entities. The nodes can be ordered in the direction of increasing curvilinear abscissa. If this is not the case and if the crack background is given by a list of cells or groups of cells, the operator will order the nodes by defining an origin node.

Two initial configurations of the upper and lower lips are taken into account to define the direction of propagation and the lips.

This operator creates a fond_fiss concept that can be used by operators CALC_G [U4.82.03] and POST_K1_K2_K3 [U4.82.05].