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arXiv · 1510.01475

Simple-average expressions for shear-stress relaxation modulus

J. P. Wittmer·H. Xu·J. Baschnagel
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Abstract

Focusing on isotropic elastic networks we propose a novel simple-average expression $G(t) = μ_A - h(t)$ for the computational determination of the shear-stress relaxation modulus $G(t)$ of a classical elastic solid or fluid and its equilibrium modulus $\G_{eq} = \lim_{t \to \infty} G(t)$. Here, $μ_A = G(0)$ characterizes the shear transformation of the system at $t=0$ and $h(t)$ the (rescaled) mean-square displacement of the instantaneous shear stress $\hatτ(t)$ as a function of time $t$. While investigating sampling time effects we also discuss the related expressions in terms of shear-stress autocorrelation functions. We argue finally that our key relation may be readily adapted for more general linear response functions.

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J. P. Wittmer, H. Xu, J. Baschnagel. 2015-10-06. Simple-average expressions for shear-stress relaxation modulus. https://doi.org/10.1103/physreve.93.012103

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