Multiscale Simulation of the Responses of Discrete Nanostructures to Extreme Loading Conditions Based on the Material Point Method

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. An interfacial scheme is being developed that can be used to effectively cast spatial discretization at different scales into a unified MPM framework. The advantage is that the interactions among discrete nanostructures can be simulated without the need for master/slave nodes as required in the Finite Element Method and other similar mesh-based methods. The multiscale simulation scheme is applied to several prototypical cases: tensile extension of a nanorod, isothermal compression of a nano-cube 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 qualitative agreement with the predictions obtained using a DPD-only description and all-atom MD, but require less computational time compared to all-atom simulations.