Analysis of Fracture Parameters for Compact-Tension-Shear Specimen of Orthotropic Materials

Treating orthotropic materials as isotropic for strength analysis and design can introduce significant errors, resulting in considerable safety risks. Furthermore, in practical conditions, cracks often exhibit mixed-mode fracture behavior, and the combination of orthotropy mechanics gives rise to an even more complex stress field in the vicinity. In this context, performing Compact-Tension-Shear (CTS) tests is a promising research methodology to determine fracture toughness of orthotropic materials in mixed mode I&II. Therefore, this study conducted a comprehensive two-dimensional finite element analysis (2D FEA) on orthotropic CTS specimens to assess critical parameters in fracture toughness including stress intensity factors (SIF) and crack mouth opening displacement (CMOD) compliance. The analysis matrix encompassed a wide range of material orthotropy, crack length ratios, and loading angles. Results showed that the impact of orthotropy varies under different geometries and loading angles, while different fracture parameters exhibit varying degrees of sensitivity to orthotropy. The obtained results would contribute to the development of fracture toughness testing methods for orthotropic materials under mixed-mode loading and provide a reference for standardization in the process.