A Non-local XFEM-Based Methodology for Modeling Mixed-mode Fracturing of Anisotropic Rocks

One of the complexities of rock engineering is predicting the fracture, especially in cases where the rock material exhibits anisotropy in both elastic and fracture properties. In this study, a fracture criterion based on a stress averaging procedure using a combination of the extended finite element method (XFEM) and the cohesive zone model (CZM) is proposed to predict the fracture growth in anisotropic rocks subjected to mixed mode I/II loadings. The precision of the proposed model is scrutinized by comparing its predictions for fracture load, fracture initiation angle and fracture path with the experimental results conducted on Grimsel granite. Finally, a discussion is presented on the effects of the important model parameters such as the mesh size dependency and the radius of the averaging zone. The proposed model is proven to be robust and reveals very good estimations for fracture parameters.

Automated summary

One complexity in rock engineering is predicting fractures in rocks with anisotropy in both elastic and fracture properties. This study proposes a fracture criterion based on a stress averaging procedure using a combination of the extended finite element method (XFEM) and the cohesive zone model (CZM) to predict fracture growth in anisotropic rocks subjected to mixed mode I/II loadings. The precision of the proposed model is evaluated by comparing its predictions with experimental results on Grimsel granite, and the effects of important model parameters are discussed.