Improved peridynamic model and its application to crack propagation in rocks

Abstract

The conventional bond-based peridynamics (BB-PD) model is suitable for simulating the failure mode of homogeneous elastic-brittle materials. However, the strain hardening and subsequent strain softening characteristics of rocks under loading cannot be reflected. In addition, the fracture mechanisms of rock materials under tension and compression are completely different. To solve these problems, this paper proposes an improved BB-PD model using different fracture criteria in the tensile and compression stages of the bond based on previous improved models, and a critical failure condition obeying the Weibull distribution is introduced to reflect the heterogeneity of the rock. The crack propagation processes of an intact rock specimen, rock specimen with a single pre-existing flaw and rock specimens with two and three pre-existing flaws under compressive loading are simulated using the model, and its feasibility is verified by comparing with the results of previous laboratory tests. Next, the effects of the inclination angle and length on the wing crack propagation length are studied. Finally, the changes in the crack aggregation modes under different rock bridge inclination angles are simulated. Eight types of crack aggregation modes are found, and the conditions under which they may occur are analysed. The improved model proposed can effectively simulate the crack propagation and coalescing processes and has a wide application prospect for rock fracture simulations.

Data‐driven nonlocal model for fragmentation in the crushing of solids

“…The application of peridynamics to the growth of defects in rocks has been demonstrated by several authors. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] In contrast to these works, the present study does not start with initial defects, but instead uses the peridynamic framework to implement failure between cells of predefined sizes and strengths.…”

Numerical Simulation Analysis of Fracture Propagation in Rock Based on Smooth Particle Hydrodynamics

“…In recent years, researchers have been applying novel numerical simulation methods to the calculation of rock fracture propagation. Zhou proposed a micro-elastic/plastic constitutive model that conforms to the mechanical characteristics of rock materials, and introduced the Weibull distribution function to reflect the heterogeneity of rocks [18]. The numerical manifold method employs two sets of independent mathematical and physical grids to solve both continuous and discontinuous problems in a unified manner.…”