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Updated: Sep 25, 2026

Studying Large Amplitude Oscillatory Shear Response of Soft Materials
Published on: April 25, 2019
Crossover between short- and long-time behavior of stress fluctuations and viscoelasticity of liquids
Siegfried Hess1, Martin Kröger, Denis Evans
1Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstrasse 36, Germany.
Abstract:
An effective viscosity coefficient is introduced based on definite time averages of equilibrium stress fluctuations rather than stress correlations. Analysis of this quantity via molecular dynamics of a simple model liquid reveals a crossover between the expected short-time elastic and the long-time viscous behavior with increasing averaging time. The procedure allows us to extract the zero-rate shear viscosity when the averaging time becomes one order of magnitude larger than the relevant relaxation time. A relationship between this effective viscosity and the dynamic viscosities is established.
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