Quantum-Atomic-Continuum-Coupled Model for Mechanical Behaviors in Micro-nano Simulations

摘要

For the numerical simulations of physical and mechanical behaviors ofmaterials at the micro-nano scale, a coupled model with the effect of localquantum is presented in this paper. Unlike traditional methods, the transitionregion is not needed since the non-local mechanical effects and theconstitutive relations are naturally involved by first principle densityfunctional calculations. In order to identify and calculate the mechanicalquantities at different scales, some necessary assumptions are made whensolving Kohn-Sham equations. Basic deformation elements are introduced andmechanical tensors are explicitly derived based on the complex Bravais lattice.The responses of 3-demensional copper nanowires which composed of 25313 atomsunder different external loads are simulated. Strain and stress fields arecalculated and dislocation distributions are predicted during the damageprocess. Numerical results confirm the validity and transferability of thismodel.