MD/FE Multiscale Modeling of Contact

Abstract

Limitations of single scale approaches to study the complex physics involved in friction have motivated the development of multiscale models. We review the state-of-the-art multiscale models that have been developed up to date. These have been successfully applied to a variety of physical problems, but that were limited, in most cases, to zero Kelvin studies. We illustrate some of the technical challenges involved with simulating a frictional sliding problem, which by nature generates a large amount of heat. These challenges can be overcome by a proper usage of spatial filters, which we combine to a direct finite-temperature multiscale approach coupling molecular dynamics with finite elements. The basic building block relies on the proper definition of a scale transfer operator using the least square minimization and spatial filtering. Then, the restitution force from the generalized Langevin equation is modified to perform a two-way thermal coupling between the two models. Numerical examples are shown to illustrate the proposed coupling formulation.

Multi-scale simulation of three-dimensional thin-film lubrication

“…Moreover, a hybrid atomistic/continuum modeling for two-dimensional contact and dry friction between the solid substrates has been proposed [25,26]. Recently, for three-dimensional (3D) contact, a multi-scale coupling of the molecular dynamics and the finite element method has been reported [27]. However, to the best of our knowledge, multi-scale simulation of 3D thinfilm lubrication considering the effects of elastic substrates has not been reported.…”