Fluctuation-dissipation relation between shear stress relaxation modulus and shear stress autocorrelation function revisited

Abstract : The shear stress relaxation modulus G(t) may be determined from the shear stress (tau) over cap (t) after switching on a tiny step strain gamma or by inverse Fourier transformation of the storage modulus G'(omega) or the loss modulus G `'(omega) obtained in a standard oscillatory shear experiment at angular frequency.. It is widely assumed that G(t) is equivalent in general to the equilibrium stress autocorrelation function C(t) = beta V which may be readily computed in computer simulations (beta being the inverse temperature and V the volume). Focusing on isotropic solids formed by permanent spring networks we show theoretically by means of the fluctuation-dissipation theorem and computationally by molecular dynamics simulation that in general G(t) = G(eq) + C(t) for t > 0 with G(eq) being the static equilibrium shear modulus. A similar relation holds for G'(omega). G(t) and C(t) must thus become different for a solid body and it is impossible to obtain G(eq) directly from C(t).
Type de document :
Article dans une revue
Molecular Physics, Taylor & Francis, 2015, 113 (17-18, SI), pp.2881-2893. 〈10.1080/00268976.2015.1023225〉
Liste complète des métadonnées

https://hal.univ-lorraine.fr/hal-01515839
Contributeur : Lcp-A2mc Ul <>
Soumis le : vendredi 28 avril 2017 - 11:14:41
Dernière modification le : jeudi 15 mars 2018 - 01:33:58

Lien texte intégral

Identifiants

Citation

J. P. Wittmer, H. Xu, O. Benzerara, J. Baschnagel. Fluctuation-dissipation relation between shear stress relaxation modulus and shear stress autocorrelation function revisited. Molecular Physics, Taylor & Francis, 2015, 113 (17-18, SI), pp.2881-2893. 〈10.1080/00268976.2015.1023225〉. 〈hal-01515839〉

Partager

Métriques

Consultations de la notice

76