Научные семинары лаборатории 27 июня
Во вторник, 27 июня прошли два очередных научных семинара Международной лаборатории суперкомпьютерного атомистического моделирования и многомасштабного анализа. С двумя докладами на тему "Collective nonaffine displacements of atoms in periodically deformed and quiescent binary glasses" выступил главный научный сотудник лаборатории, профессор Wright State University (США) Приезжев Николай Вячеславович.
Title: Collective nonaffine displacements of atoms in periodically deformed and quiescent binary glasses. Part I
Abstract: In the first part of the presentation, we will cover selected topics on collective particle dynamics in glassy materials near the glass transition, deformation of amorphous materials at low temperature, and sample preparation.
Title: Collective nonaffine displacements of atoms in periodically deformed and quiescent binary glasses. Part II
Abstract: The influence of periodic shear deformation on nonaffine atomic displacements in an amorphous solid is examined via molecular dynamics simulations. We study the three-dimensional Kob-Andersen binary mixture model at a finite temperature. It is found that when the material is periodically strained, most of the atoms undergo repetitive nonaffine displacements with amplitudes that are broadly distributed. We show that particles with large amplitudes of nonaffine displacements exhibit a collective behavior; namely, they are organized into compact clusters that become comparable with the system size near the yield strain. With increasing strain amplitude, spatial correlations of nonaffine displacements become increasingly long-ranged, although they remain present even in a quiescent system due to thermal fluctuations. Furthermore, we find that near the critical strain amplitude, the amplitude of shear stress oscillations decreases after the first several cycles, which is accompanied with the formation of shear bands.