A pseudo-spring based fracture model for SPH simulation of impact dynamics

A strategy is developed to model crack initiation and propagation within Smoothed Particle Hydrodynamics (SPH)-based simulation of solids under impact. While discretizing the continuum, an efficient immediate neighbor interaction is formulated by using suitable spring-like connectivity among discrete particles. Degradation of the spring forces between particles is determined through a material damage evolution law. In order to modify the level of interaction between particles, an interaction coefficient is introduced in the conservation equations. This interaction coefficient is determined based on the accumulated damage in the connecting springs. A fully damaged spring is considered as the initiation of crack between connected particles. The propagation of the crack path is captured through the sequence of such damaged springs. However, the neighbors connected by those damaged springs will interact in case of crack closure, transferring compression as in the case between two free surfaces. The superior performance of the proposed strategy is demonstrated via few examples.