A computational approach for handling complex composite microstructures

A current challenge concerning materials known as ceramic-matrix composites (CMCs) resides in the development of qualitative tools for application-oriented material design optimization. The phenomena and morphology must be dealt with on the smallest scale because they impact the global material response directly. In order to handle the associated high level of complexity, we propose a new GFEM-like approach for modeling the CMC yarn, which is considered to be an appropriate modeling scale. This model relies on a pattern-based description of the microscale embedded within a GFEM-like framework. The classical difficulties associated with the implementation and computation cost of the GFEM are dealt with through a multiscale approach based on the Saint Venant principle. This multiscale vision enables the microstructure and the microkinematics to be handled on the scale of the pattern regardless of the discretization on the macroscale. This new multiscale method is applied to the 2D modeling of the cross-section of a CMC yarn, then extended to a simple 3D yarn section. The key question of pattern selection is also discussed.