Srikanth Sastry

Srikanth Sastry is a Professor at the Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India. His research interests have been in the area of statistical mechanics, with a focus on understanding a range of unusual and interesting properties of liquids and other soft condensed matter, which he addresses with computation as a major tool. Some of the areas of his research activities are: Slow dynamics and the glass transition in supercooled liquids; Mechanical properties of glasses and other amorphous solids and their yielding behavior; Routes to jamming in sphere packings, in particular, shear jamming; Memory formation and adaptable materials; Anomalous thermodynamic and dynamical properties, liquid-liquid phase transitions in water, silicon and other network forming liquids; Self assembly design and addressable self assembly; Glassy behaviour and associated phenomena in biological matter.

Abstract Title: Yielding and fatigue failure in sheared glasses

The mechanical response of glasses, particularly their plasticity and failure, is of extremepractical importance. When glasses are subjected to repeated cycles of stress or deformation, they can failafter several cycles. The microscopic understanding of the initiation of such fatigue failure continues to be ofinterest, to elucidate further. Glasses exhibit interesting non-monotonic behavior, with deformation inducedannealing preceding failure, which cannot be neatly fit into conventional descriptions of fatigue failure, e. g., inmetals. The extent to which the description of fatigue failure in amorphous solids may differ from that incrystalline, metallic, solids, is thus an open question of interest. Employing computer simulations of a modelglass, we investigate the failure time for shear amplitudes above the fatigue limit. The failure times exhibit apower law divergence at the fatigue limit, and broad sample-to-sample variation, which we characterize andattempt to rationalize. We explore several measures of damage, based on quantifications of plasticrearrangements and on dissipated energy. Failure times exhibit striking correlations with accumulatedplasticity, which surprisingly permit accurate prediction of failure times from the damage accumulated in theinitial cycles. These numerical results, as well as approaches to developing a microscopic picture of fatiguefailure in amorphous solids, will be discussed.