An extended peridynamic model equipped with a new bond-breakage criterion for mixed-mode fracture in rock-like materials

This paper develops a numerical model based on two-parameter extended bond-based peridynamics with a new bond-breakage criterion to simulate mixed-mode fracture in rock-like materials. This model requires only four basic parameters: Young's modulus, Poisson's ratio, and Mode-I and Mode-II energy release rates. Tensile and shear cracks can be distinguished explicitly from mixed-mode fracture phenomena by decomposing the bond potential into dilatational and deviatoric terms. The m- and delta-convergence studies are first performed on the gypsum specimen with a single flaw subjected to uniaxial compression. The initialization and propagation of wing cracks (tensile cracks), quasi-coplanar and oblique secondary cracks (shear cracks) are successfully captured. As an example application, the crack initiation, propagation and coalescence processes of gypsum specimens with various double-flaw configurations are investigated. Under uniaxial compression, three typical types of crack coalescence patterns characterized by shear cracking or mixed tensile-shear cracking are obtained. In all cases, the numerical results predicted by the developed approach agree well with the experimental observations, both qualitatively and quantitatively. (c) 2023 Elsevier B.V. All rights reserved.

Automated summary

This paper presents a numerical model for simulating mixed-mode fracture in rock-like materials using a two-parameter extended bond-based peridynamics. The model incorporates a new bond-breakage criterion and requires only four basic parameters. Experimental validation is conducted on gypsum specimens, demonstrating good agreement between the numerical and experimental results.