1. Introduction

Before thinking about introducing a new type of mesh in Code_Aster, you need to have:

• consulted the U3.01.00 documentation (« description of the Code_Aster mesh file ») in order to know the writing conventions (order of the nodes,…),

• consulted the R3.01.01 documentation (« shape functions of isoparametric elements ») in order to know the representations of the reference elements, their shape functions, the families of existing Gauss points,…

After having:

• sized your element,

• placed the knots,

• determined the functions of forms and their derivatives,

• awarded one or more families of Gauss points,

You can move on to the next step, which is to introduce your mesh or reference element into Code_Aster.

This step involves modifying the source of Code_Aster, i.e. modifying:

• element catalogs,

• fortran files.

We will explicitly describe the interventions in each of the files concerned.

After this step, you can perform calculations on models that accept your new element type. It is interesting to be able to print, visualize and/or review your results. It is therefore not possible to restore your development without updating the pre-processing and post-processing commands. We will list the routines concerned.

At this stage, it remains to check that all the functionalities of Code_Aster are still operational. We will see that the source for other operators will need to be updated. We will list the operators and routines involved.

With the development phase finalized, there is still the validation phase. The various tests to be carried out will be presented in this document.

Finally, the documentation will have to be updated. We will list the various documentations to be enriched.

In order to review these different steps, we will present an example illustrating the addition of a new mesh and a reference element.