Research on wing crack propagation of closed crack under uniaxial compression based on peridynamics

To investigate the influence of the interaction between closed crack surfaces on crack propagation, a nonlocal friction contact model is proposed for numerical simulation of wing crack propagation under uniaxial compression. The closed cracks with different inclination angles are defined by mathematical models, and cracks are generated by breaking off bonds at specific positions. In terms of numerical model validation, the comparison with FEM results indicates the correctness of the friction contact numerical model. Subsequently, the maximum principal stress criterion was applied to determine the breakage of the bond. The simulation results showed that under uniaxial compression, the closed crack tips undergo tensile failure, and the wing cracks will gradually expand towards the direction of the maximum principal stress. Both the crack inclination angle alpha and friction coefficient fc have an impact on crack initiation and propagation, increasing alpha or fc will reduce the initiation angle theta of crack propagation. At the same inclination angle alpha, the larger the friction coefficient fc, the shorter the crack propagation length, while the smaller the inclination angle alpha, the more significant the influence of friction coefficient fc on the initiation angle theta and crack path.