You are here: MIMS > EPrints
MIMS EPrints

2006.203: Ageing and rheology in soft materials

2006.203: S.M. Fielding and P. Sollich (2000) Ageing and rheology in soft materials. Journal of Rheology, 44 (2). pp. 323-369. ISSN 0148-6055

Full text available as:

PDF - Archive staff only - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
379 Kb

DOI: 10.1122/1.551088

Abstract

We study theoretically the role of aging in the rheology of soft materials. We define several generalized rheological response functions suited to aging samples (in which time translation invariance is lost). These are then used to study aging effects within a simple scalar model (the "soft glassy rheology" or SGR model) whose constitutive equations relate shear stress to shear strain among a set of elastic elements, with distributed yield thresholds, undergoing activated dynamics governed by a "noise temperature," x. (Between yields, each element follows affinely the applied shear.) For 1 < x < 2 there is a power-law fluid regime in which transients occur, but no aging. For x < 1, the model has a macroscopic yield stress. So long as this yield stress is not exceeded, aging occurs, with a sample's apparent relaxation time being of order its own age. The (age-dependent) linear viscoelastic loss modulus G[double-prime](omega,t) rises as frequency is lowered, but falls with age t, so as to always remain less than G[prime](omega,t) (which is nearly constant). Significant aging is also predicted for the stress overshoot in nonlinear shear startup and for the creep compliance. Though obviously oversimplified, the SGR model may provide a valuable paradigm for the experimental and theoretical study of rheological aging phenomena in soft solids. ©2000 Society of Rheology.

Item Type:Article
Subjects:MSC 2000 > 76 Fluid mechanics
MSC 2000 > 82 Statistical mechanics, structure of matter
MIMS number:2006.203
Deposited By:Miss Louise Stait
Deposited On:19 July 2006

Download Statistics: last 4 weeks
Repository Staff Only: edit this item