基于Mohr‑Coulomb强度准则的非线性近场动力学岩石破坏计算方法OA

This study develops a numerical model for analyzing and solving stress and strain fields within the nonlocal differential operator framework,enabling the direct calculation of stress components at different time steps.Based on the small-deformation assumption,the nonlocal force density is reconstructed using the operator formulation,thereby avoiding the need for additional surface correction.A stretch-dependent weakening coefficient is introduced to characterize the nonlinear deformation and failure behavior of rock materials.The tensile,compressive,and shear damage of bonds between material points is evaluated using the tensile strength,compressive strength,and Mohr‑Coulomb criterion,and a nonlinear Mohr‑Coulomb‑based peridynamic damage model for rock fracture is established.The proposed model is applied to investigate crack initiation,propagation,and damage evolution of intact sandstone specimens and sandstone specimens containing prefabricated orthogonal intersecting fissures under different loading conditions.The results show that the proposed method effectively simulates mixed tensile–shear fracture processes in both intact and flawed rock specimens,overcoming the limitation of conventional methods in distinguishing different fracture modes.