Generalities =========== The cara_elem data structure is a set of maps [:external:ref:`D4.06.05 `] that contain information assigned to the finite elements of the model. In general, this information concerns structural elements: shells, beams,... it is for example the thickness of the shells, the inertia characteristics of the beams,... CARA_ELEM is also used to assign an orientation (a local coordinate system) to isoparametric elements. This orientation is necessary if, for example, the material is not isotropic.