Multiscale simulation of the responses of discrete nanostructures to extreme loading conditions based on the material point method

摘要

A particle-based multiscale simulation procedure is being developed that includes a concurrent link between the Material Point Method (MPM) and Dissipative Particle Dynamics (DPD) and a hierarchical bridge from Molecular Dynamics (MD) to DPD. In this paper, an interfacial scheme is presented that can be used to effectively cast spatial discretization at different scales into a unified MPM framework. The advantage to the approach is that the interactions among discrete nanostructures under extreme loading conditions can be simulated without the need for master/slave nodes as required in the Finite Element Method and other similar mesh-based methods. The proposed multiscale simulation scheme is applied to representative cases: tensile extension of a single nanobar, isothermal compression of a cube-shaped nanoparticle in a high-pressure fluid, and the behavior of nanosphere pairs and nanosphere-nanorod assemblies in a confining fluid for different initial arrangements of the components. The concurrent DPD/MPM results are in good qualitative agreement with the predictions obtained using a DPD-only description and all-atom MD, but require much less computational time as compared to all-atom simulations. (C) 2015 Elsevier B.V. All rights reserved.