Berlin 2012 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 8: Glasses I (with CPP, talks by CPP)
DY 8.3: Talk
Monday, March 26, 2012, 16:00–16:15, C 243
Heterogeneous shear in hard sphere glasses — •Fathollah Varnik1,2, Suvendu Mandal2, and Dierk Raabe2 — 1ICAMS, Ruhr University Bochum, Germany — 2Max-Planck-Institut fuer Eisenforschung, Duesseldorf, Germany
There is growing evidence that the flow of driven amorphous solids is not homogeneous, even if the macroscopic stress is constant across the system [1,2]. Via event driven molecular dynamics simulations of a hard-sphere glass, we provide first direct evidence for a correlation between the fluctuations of the local volume-fraction and the fluctuations of the local shear rate [3]. Higher shear rates do preferentially occur at regions of lower density and vice versa. The temporal behavior of fluctuations is governed by a characteristic time scale, which, when measured in units of strain, is independent of shear rate in the investigated range. Interestingly, the correlation volume is also roughly constant for the same range of shear rates. A possible connection between these two observations is discussed.
[1] F. Varnik, L. Bocquet, J.-L. Barrat, L. Berthier, Phys. Rev. Lett. 90, 095702 (2003).
[2] R. Besseling, L. Isa, P. Ballesta, G. Petekidis, M.E. Cates, W.C.K. Poon, Phys. Rev. Lett. 105, 268301 (2010).
[3] S. Mandal, M. Gross, D. Raabe, F. Varnik, submitted to Phys. Rev. Lett.