Quasi-brittle fracture simulation by using discretized virtual internal bond with a trilinear damage potential

Abstract

To more accurately simulate the fracture propagation in a quasi-brittle material, a trilinear damage potential is developed, which accounts for both the damage and fracture energy. The bond potential is divided into three stages, namely the linear elastic, the pre-peak damage and the post-peak damage stage. Once the bond enters the damage stage, it can be completely unloaded without any residual irreversible deformation. This potential is embedded into the discretized virtual internal bond (DVIB) model to simulate the failure process of quasi-brittle material. The simulation examples suggest that it can capture the damage behavior of material in both the pre-peak and the post-peak stage. The mesh size sensitivity can be significantly relieved due to the embedded fracture energy in the bond potential. How significant the micro bond parameter plays a role is size-dependent. The simulation results suggest that the DVIB with this potential can well simulate the fracturing process of brittle material. It provides an effective lattice method to simulate the failure process of a quasi-brittle material with consideration of damage.