Molecular Dynamics Simulation for Crack Propagation in Magnesium Alloy

Abstract

In this work, crack initiation due to the pre-existence of an initial crack has been predicted according to the criterion of critical stress intensity factor and succeeding crack evolution and propagation are also been performed using molecular dynamic (MD) method in combination with finite element method (FEM). The modified embedded atom method potentials were employed to characterize the interaction among atoms in magnesium alloy in MD simulation. Finite element simulations have been first conducted to provide subsequent MD simulation with boundary conditions constrained at the atoms. The MD simulation shows that atoms around crack arrange disorderly, aggravate rapidly suggesting the onset of crack initiation and eventually results in the failure of alloy specimen. It helps to evaluate the value of critical stress intensity factor for a specific crack configuration, which provides an effective way to determine the stress intensity factor for the specified configuration.