1. But

Define the behavior of a single crystal, a polycrystal or a multifiber beam.

For the behavior of a single crystal or a polycrystal, the user is allowed to choose the components of the law of monocrystalline behavior.

According to this definition, only the name of the crystallographic structure is given, knowing that the directions of the sliding systems of each family of sliding systems are defined once and for all in the source code.

In the case of a multi-fiber beam, this operator makes it possible to associate an incremental behavior with a group of fibers.