A particle‐continuum coupling method for multiscale simulations of viscoelastic–viscoplastic amorphous glassy polymers

Molecular dynamics simulations of glassy polymers

We review recent results from computer simulation studies of polymer glasses, from chain dynamics around glass transition temperature Tg to the mechanical behaviour below Tg. These results clearly show that modern computer simulations are able to address and give clear answers to some important issues in the field, in spite of the obvious limitations in terms of length and time scales. In the p...

Diffusion of Small Molecules in Amorphous Glassy Polymers

Modeling the viscoelastoplastic behavior of amorphous glassy polymers

Constitutive equations are derived for the viscoelastoplastic response of amorphous glassy polymers at isothermal loading with small strains. A polymer is treated as an ensemble of cooperatively relaxing regions (CRR) which rearrange at random times as they are thermally agitated. Rearrangement of CRRs reflects the viscoelastic response of the bulk medium. At low stresses, CRRs are connected wi...

Approximate ab initio simulations of amorphous silicon and glassy chalcogenides

A classic problem of materials theory is to understand the properties of glasses and amorphous materials. Comprehension of disordered systems requires as an initial step atomistic models (coordinates of the atoms) that reproduce the known experimental features of the material. This includes structural (diffraction) information of course, but also higher-order correlations (as from new fluctuati...

Time-step coupling for hybrid simulations of multiscale flows

A new method is presented for the exploitation of time-scale separation in hybrid continuummolecular models of multiscale flows. Our method is a generalisation of existing approaches, and is evaluated in terms of computational efficiency and physical/numerical error. Comparison with existing schemes demonstrates comparable, or much improved, physical accuracy, at comparable, or far greater, eff...