Adaptive phase field modelling of crack propagation in orthotropic functionally graded materials

In this work, we extend the recently proposed adaptive phase field method to model fracture in orthotropic functionally graded materials (FGMs). A recovery type error indicator combined with quadtree decomposition is employed for adaptive mesh refinement. The proposed approach is capable of capturing the fracture process with a localized mesh refinement that provides notable gains in computational efficiency. The implementation is validated against experimental data and other numerical experiments on orthotropic materials with different material orientations. The results reveal an increase in the stiffness and the maximum force with increasing material orientation angle. The study is then extended to the analysis of orthotropic FGMs. It is observed that, if the gradation in fracture properties is neglected, the material gradient plays a secondary role, with the fracture behaviour being dominated by the orthotropy of the material. However, when the toughness increases along the crack propagation path, a substantial gain in fracture resistance is observed. (C) 2020 China Ordnance Society. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co.

Automated summary

The adaptive phase field method is extended to model fracture in orthotropic functionally graded materials, using a recovery type error indicator and quadtree decomposition for adaptive mesh refinement. Results show an increase in stiffness and maximum force with increasing material orientation angle, and a substantial gain in fracture resistance when toughness increases along the crack propagation path. The study emphasizes the importance of considering material gradients and orthotropy in fracture behavior analysis in orthotropic FGMs.