A method of seamlessly combining a crack tip molecular dynamics enclave with a linear elastic outer domain in simulating elastic-plastic crack advance

Molecular dynamics is applicable only to an extremely small region of simulation. In order to simulate a large region, it is necessary to combine molecular dynamics with continuum mechanics. Therefore, we propose a new model where molecular dynamics is combined with micromechanics. In this model, we apply molecular dynamics to the crack tip region and apply micromechanics to the surrounding region. Serious problems exist at the boundary between the two regions. In this study, we manage to solve these problems, and make possible the simulation of the process of crack propagation at the atomic level. In order to examine the validity of this model, we use α-iron for simulation. If the present model is valid, stress and displacement should vary continuously across the boundary between the molecular dynamics region and the micromechanics region. Our model exhibits just such behavior.