A contact mechanics model for quasi-continua

A computational multiscale contact mechanics model is proposed to describe the interaction between deformable solids based on the interaction of individual atoms or molecules belonging to the solids. The contact model, formulated in the framework of large deformation continuum mechanics, is derived from coarsening the molecular dynamics (MD) description of a large assembly of individual atoms, and it thus bears some of the characteristics of the underlying atomic structure. The multiscale contact model distinguishes between atoms interacting within a small neighbourhood within the solids and atoms interacting over large distances between remote regions of the solids. The former furnishes a constitutive relation for the continuum, like the Cauchy–Born Rule, while the latter is used to model the interaction between distinct bodies. The proposed contact model is formulated as a variational weak form and implemented within an updated Lagrangian finite element method. It is shown that, as the problem size increases, the description of the model can be simplified to yield more efficient computational algorithms. In this respect, the proposed multiscale formulation leads to a smooth transition from MD to continuum contact mechanics. The general behaviour of the contact model is studied, and some numerical examples are given. Copyright q 2007 John Wiley & Sons, Ltd.