![]() Several physical tests have been conducted on the propagation processes of the rock specimen with a single pre-existing flaw and multiple pre-existing flaws with different lengths and inclination angles. Therefore, it is of great significance to study the initiation, propagation and coalescence of the cracks in rocks for the prevention and control of natural disasters. The cracks in rocks may cause tunnel collapse, dam cracking, overturning of buildings and other engineering accidents. The improved model proposed can effectively simulate the crack propagation and coalescing processes and has a wide application prospect for rock fracture simulations.Ī rock is a type of heterogeneous and discontinuous material containing many flaws such as primary cracks of different sizes and directions which has experienced complex geological tectonic processes. Eight types of crack aggregation modes are found, and the conditions under which they may occur are analysed. Finally, the changes in the crack aggregation modes under different rock bridge inclination angles are simulated. ![]() Next, the effects of the inclination angle and length on the wing crack propagation length are studied. 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. ![]() 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. In addition, the fracture mechanisms of rock materials under tension and compression are completely different. However, the strain hardening and subsequent strain softening characteristics of rocks under loading cannot be reflected. ![]() The conventional bond-based peridynamics (BB-PD) model is suitable for simulating the failure mode of homogeneous elastic-brittle materials. ![]()
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