Feasibility of a weakly intrusive Generalized Finite Element Method implementation in a commercial code: Application to Ceramic Matrix Composite micro-structures

摘要

As the development of new grades of Ceramic Matrix Composites (CMC) for civil aviation grows, different manufacturing processes have been perfected and several of them can be used successively in order to obtain different types of micro-structures and a variable material quality. Consequently a versatile model should be developed in order to compare these materials and create a tool to help engineers to predict the mechanical behavior at the fiber scale. Here the Generalized Finite Element Method (GFEM) is proposed. It consists in enriching the classical Finite Element (FE) approached displacement by numerical functions to deliver an accurate description of the fiber-scale structure while limiting the number of degrees of freedom compared to a classical finite element description. A pattern-based description of the microscale is depicted using an industrial code for an engineering purpose. Four main difficulties are highlighted (i) the choice of the enrichment functions regarding the literature (ii) their stiffness matrix computation in a commercial code (iii) the construction of the pattern-based structure and (iv) the post-processing. Two GFEM strategies are presented and demonstrate the feasibility of an enriched kinematics within a classical finite element modeler. The selection of such modeler is conditioned by the possibility of weakly intrusive automation of the various stages of construction of the enriched patterns with the help of an external scripting language. (C) 2020 Elsevier Ltd. All rights reserved.