Verification of reinforcement isotropic solid model in conjunction with maximum shear stress criterion to anticipate mixed mode I/II fracture of composite materials

Abstract

In the present research, a new criterion based on maximum shear stress (MSS) theory is developed for fracture investigation of orthotropic materials under mixed mode I/II loading. The crack is assumed to be embedded both along and across the fibers in the isotropic matrix. Self-similar crack propagation is assumed based on experimental observations and the reinforcement isotropic solid (RIS) concept is utilized for theoretical derivation of the criterion. In this model, an istropic crack tip stress field is assumed and the effects of fibers are supposed as stress reduction factors. The superiority of employing MSS theory in conjunction with RIS model is proved by derivation of a direct MSS-based mixed mode fracture criterion with respect to the orthotropic crack tip stress field. Verification of the results is performed by comparison of the fracture limit curves with available experimental mixed mode fracture data.