Analysis of three-dimensional fracture mechanics problems: A non-intrusive approach using a generalized finite element method

This paper shows that the generalized finite element method with global-local enrichment functions (GFEM ^gl) can be implemented non-intrusively in existing closed-source FEM software as an add-on module. The GFEM ^gl is based on the solution of interdependent global (structural) and local (crack) scale problems. In the approach presented here, an initial global scale problem is solved by a commercial finite element analysis software, local problems containing 3-D fractures are solved by an hp-adaptive GFEM software and an enriched global scale problem is solved by a combination of the FEM and GFEM softwares. The interactions between the solvers are limited to the exchange of load and solution vectors and does not require the introduction of user subroutines to existing FEM software. As a results, the user can benefit from built-in features of available commercial grade FEM software while adding the benefits of the GFEM for this class of problems. Several three-dimensional fracture mechanics problems aimed at investigating the applicability and accuracy of the proposed two-solver methodology are presented.