Friday, October 2, 3:30 p.m.

PRESENTER: Vladimir V. Payulin, Center for Computational & Data-Intensive Science and Engineering; Skolkovo Institute of Science and Technology 
TITLE: The Prediction of Viscoelastic Properties of Polymer Glasses
ABSTRACT: Prediction of material properties based on the molecular structure remains one of the most interesting and relevant problems of modern physics and material science. For materials with regular atomistic structure such as crystals the periodicity simplifies the description and allows to build robust computational models. However, amorphous solids (glasses) are notoriously difficult to describe due to a random nature of a local packing. Yet, these are materials which are ubiquitous in practical applications and possess very rich physical behaviour. Some time ago a new athermal approach for the calculation of viscoelasticity of glasses was proposed by A. Lemaitre and C. Maloney (J. Stat. Phys., 2006). The theory takes into account additional relaxations which atoms perform due to the lack of local packing symmetry. Technically it requires a computation of eigenvalues and eigenvectors of the Hessian matrix. In our presentation we will use polymer glasses as a simple model system which will be used to illustrate how to tackle the unresolved case of finite temperatures, how to generalise the approach for multicomponent systems and how to circumvent enormous memory and time requirements for simulation of atomistic amorphous systems. We will compare the theoretical results with the molecular dynamics simulations and show a nice agreement within the wide range of parameters.

Zoom link Meeting ID: 946 6432 9237 Passcode: 166470