1. Introduction#

This document describes the numerical implementation in Code_Aster of the « Large Shifts with X- FEM » approach. In particular, we present the Fortran routines that build the Code_Aster operators necessary to build the X- FEM model, as well as the tree structure of these operators.

The document is written for the people who will continue this work (interns, doctoral students, or post-docs) and maintain it. This reading should be completed by the comments that are inserted all over the Fortran routines (new or just modified).

After this introduction, the following six chapters respect the order of operators to be defined in a Code_Aster command file in order to perform an analysis using the « Large slips with X- FEM » approach. In each chapter corresponding to an operator, its call tree is also presented where only the routines concerning this approach are shown.

We end with the presentation of development perspectives to make this new approach as general as possible.

Important notes:

  1. The numerical implementation of this approach concerns 2D (linear and quadratic) and 3D (linear) cases. The treatment of crack and multi-cracked bottom elements is possible. The friction terms have been implemented in all cases except for multi-cracked elements.

  2. This approach has been the subject of an evolution of Code_Aster driven by the forms (10708, 10751, 10752 and 10753, 11957,11958, 12608,10556, 12608,10556, 13556, 13556, 13556, 13556, 13556, 13556, 13556, 13556, 13556, 13556, 13556, 13556, 13556, 13556, 13178, 13179 and 15559). It has been operational in the code since the 9.1.14 release of version STA9 .1 and has since been updated to version STA10 .0.