1. Generalities

The material appears in many commands and is involved in most routines for calculating elementary terms (TExxxx).

In fact, and unlike other codes, we distinguish the concept of « material », defined by command DEFI_MATERIAU, and which can be archived in the form of a catalog, (see command INCLUDE_MATERIAU [U4.43.02]) from the notion of behavior used during a given calculation. The material consists of parameter values associated with a number of behavior models. In practice, these parameters are defined using simple keywords, under factor keywords from the DEFI_MATERIAU command. These factor keywords (for example ELAS, ECRO_LINE,, CIN1_CHAB, LEMAITRE) make it possible to define all or some of the parameters necessary for a behavior model. For example, the behavior (chosen by the user in STAT_NON_LINE or DYNA_NON_LINE under the keyword factor COMPORTEMENT) VMIS_CINE_LINE will use the material parameters defined under the keywords factor ELAS and ECRO_LINE of DEFI_MATERIAU. The VISC_CIN1_CHAB behavior will use the ones defined by ELAS, CIN1_CHAB, and possibly LEMAITRE.

For the sake of misnomer, in this document, we’ll call « behavior » a DEFI_MATERIAU factor keyword.

In addition, some global commands (MECA_STATIQUE, THER_LINEAIRE,…) do not allow the user to choose the behavior used for the calculation. It is therefore necessary that the calculation (for example of the stiffness matrix in the previous examples) can be done without ambiguity. This is why it is necessary for certain behaviors of the same nature (ELAS_xxx, THER_xx) to be unique in the material. By language convention in this document, we will say that all behaviors of the same nature (same prefix: ELAS, THER) belong to the same « phenomenon ». Certain « behaviors » can therefore be classified by « phenomenon » in which they are mutually exclusive.

The data structure associated with the material contains the name and values associated with the parameters that describe each behavior. Parameters can be real, complex, or functional. Within this data structure, parameter values are accessed by name.

For reasons of code performance (especially in the case of nonlinear behaviors), the coded material was introduced. The data structure associated with the coded material is temporary, it contains the addresses of the various objects constituting the master data structure. In this case, accessing the values of the parameters no longer requires the storage of JEVEUX objects and a search by name each time the material is used. However, access by name to the parameters remains.

These two data structures are based on function-type structures (constant function, parameter function, or tablecloth) and simple vector JEVEUX objects.

The creation of a data structure (function (. & RDEP) prefixed by the name of the material then makes it possible to have a permanent memory space necessary for the interpolation of the layers defining the tensile curves depending on the temperature. This data structure is created on the basis GLOBALE in order to be exchanged between the various commands in the code.