XFEM modeling of short microfiber reinforced composites with cohesive interfaces

This manuscript presents the formulation and implementation of a failure model for random short microfiber reinforced composite materials based on the Extended Finite Element Method (XFEM). Elastic and deformable microfiber inclusions modeled as objects with zero measure are incorporated into the XFEM framework. A new &bonding enrichment function is proposed to idealize the progressive debonding between the fiber-matrix interfaces. The proposed manuscript provides a modeling strategy particularly suitable for very high aspect ratio inclusions. The fiber deformation is approximated as axial and directly incorporated into the Lagrangian. The progressive failure within the matrix material is idealized using an integral-type nonlocal damage model. The performance of the proposed XFEM model is assessed by comparing model predictions to the direct finite element method for various fiber configurations. The numerical verification studies point to high accuracy characteristics of the proposed approach. The computational efficiency of the approach provides the capability to evaluate the failure response of microstructures that include a large number of short fiber inclusions. (C) 2015 Elsevier B.V. All rights reserved