Influence of micro-modulus functions on peridynamics simulation of crack propagation and branching in brittle materials

Abstract

In this work, the micro-modulus function based on response function is defined. Five types of response functions are introduced to describe the spatial distribution of the intensity of nonlocal forces in prototype micro-elastic brittle (PMB) model. By using various micro-modulus functions in numerical models, the dynamic crack propagation and crack branching are reproduced, and the influence of micro-modulus function on crack propagation, single crack branching, and successive branching is analyzed. The crack propagation and branching patterns obtained by different micro-modulus functions are in close agreement with the previous experimental results that show the path length (L) before branching decreases as the applied stress increases. The times of the crack initiation and branch initiation and propagation are sensitive to the micro-modulus function in spite of the same pattern under different stress levels. The speed for crack branching and the average and maximum speeds of crack growth are influenced by the micro-modulus function. The branching speed after the first branch cracks can slightly increase or decrease or stay constant under various micro-modulus functions.