СЕМИНАР ПО МЕХАНИКЕ СПЛОШНЫХ СРЕД

Уважаемые коллеги!

В среду, 30 октября 2019 г., в кинозале Института механики МГУ в 12.00 состоится очередное заседание семинара по механике сплошных сред под руководством А.Г. Куликовского, В.П. Карликова, О.Э. Мельника и А.Н. Осипцова.

L.M. Truskinovsky

Ecole Polytechnique, Paris

CRITICALITY IN CRYSTAL PLASTICITY

The PDE based description of crystal plasticity adopted in classical continuous theory relies on spatial homogenization and time averaging, however, such view, implying smooth plastic flow, has been recently challenged by the observations of intermittent plastic activity at the micro-scale. The observed behavior has been linked to collective depinning of dislocations from quenched and self-induced obstacles which is mediated by long-range elastic stress fields.

Detailed experimental studies have shown that both temporal and spatial structure of such plastic flows is not Gaussian and is instead described by scale free power law statistics which is a signature of critical behavior. In this talk we review the new meso-scopic theory of crystal plasticity which is based on the assumption that the elementary elastic elements are exposed to infinite energy landscape accounting for lattice invariant shears. We show that this theory allows one to capture adequately not only the averaged behavior but also the spatial and temporal complexity of plastic fluctuations reminiscent of turbulent flows.