Peridynamics for unguided crack growth prediction under mixed-mode loading

Abstract

Peridynamics enables complex crack path prediction in structures without resorting to a special treatment of mathematical singularities as in the case of classical continuum mechanics. The peridynamic equations of motion is valid everywhere even in the presence cracks. Thus, failure process is included as part of the constitutive model for crack initiation and propagation in an unguided manner. Also, peridynamics correctly redistributes the load in the presence of complex and multiple cracks for accurate prediction of residual strength of structures. This study concerns the prediction of crack propagation paths in isotropic materials under complex loading conditions by using peridynamics. Crack growth process is controlled by a single failure parameter referred to as critical stretch which can be expressed in terms of the fracture toughness of the material. The demonstration problems concern crack growth in a four-point shear specimen and a compact tension test specimens with a sink and a miss hole. All of these applications include a pre-existing crack under mixed-mode loading conditions. The simulations capture experimentally observed non-self-similar crack propagation paths.