Simulation of crack propagation with (molecular dynamics+micromechanics) model. (1st Report, Proposal and examination of a new model)

Molecular dynamics is applicable for only a small region of simulation. To simulate a large region, it is necessary to combine molecular dynamics with continuum mechanics. Therefore, we propose a new model in which molecular dynamics is combined with micromechanics. We apply a molecular dynamics model to the crack tip region and apply a micromechanics model to the surrounding region. Problems exist at the boundary. In this study, we solve the boundary problems and develop a method for combining molecular dynamics with micromechanics. We make possible the simulation of the process of crack propagation and dislocation increase. In order to examine the validity of this model, we use a-iron in simulation. If the proposed model is valid, stress and displacement must vary continuously across the boundary between the molecular dynamics region and the micromechanics region. Our results show that the two parameters vary continuously across the boundary.