Alladi Ramakrishnan Hall

Creep response of soft glassy materials

Moumita Naskar

IMSc

We study the creep response of soft glassy materials to externally applied constant shear stress via extensive numerical simulations of a model two-dimensional soft colloidal glass. While subjected to weak stress, the system is found to creep over a long period before fluidization, often beyond our numerical observational timescale. In the low temperature and weak stress limit, the associated strain rate decays following power law (1/t) as predicted analytically for such a soft glassy system. The static and dynamical yield thresholds and the gap between the two are also found to decrease with increasing temperature. Further, the microscopic behavior of the system in the creep regime and during the onset of fluidization has been explored in terms of mean square displacements and local non-affine displacements. Additionally, we have studied the recovery of the strain after removing the stress either in the arrested or creep regime. For the arrested case, the recovery is found to be independent of the waiting time whereas for the creep case, the degree of recovery decreases with increasing waiting time.