Phase-field crack analysis using estimated transition zone of crack by molecular dynamics simulation

Abstract

We calculate the parameter that governs the width of the transition zone by molecular dynamics (MD) simulation and use it in a phase-field crack (PFC) simulation with the mechanical properties of iron. First, a quantitative evaluation of intactness is conducted by examining the change in atomic conformation induced by crack propagation, whose numerical data are taken from the result of the MD simulation. The spatial distribution of the intactness is fitted to the same function as the damage parameter in the PFC model, namely, an exponential function, by the least-squares method. From this distribution, the transition zone parameter is estimated. The result of the PFC simulation using this newly determined transition zone parameter is discussed in terms of the crack path by comparison with the result of crack propagation analysis based on the MD simulation.