Age-Dependent Modes of Extensional Necking Instability in Soft Glassy Materials

Abstract

Reprinted with permission from the American Physical Society: Physical Review Letters 114, 158301 c 2015 by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modied, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

Triggers and signatures of shear banding in steady and time-dependent flows

“…It is hoped that the criteria just summarized will provide a useful field guide to the onset of necking instability in filament stretching. A fuller discussion of them can be found in [108,109], together with the manuscripts with Hoyle currently under review.…”

“…Also as before, they are expressed in terms of characteristic signatures in the shapes of the relevant underlying rheological response function for the given protocol. We now briefly summarize them, referring the reader to [108,109], and the manuscripts with Hoyle under review, for a more detailed discussion, and for comprehensive citation of the motivating literature, which is beyond the scope of this article.…”

“…We therefore now consider in turn the three common protocols of step tensile stress, step tensile force, and startup of constant Hencky strain rate. The results that we shall discuss were obtained in analytical calculations performed within highly generalized constitutive descriptions, and confirmed numerically in several models of polymer dynamics [110] (the Oldroyd B, Giesekus, fene-CR, Rolie-poly [70], and pom-pom [111] models), and in tensorial versions of the SGR and fluidity models of soft glasses [109].…”

“…With that analogy in mind, in [108,109], together with the manuscripts with Hoyle under review, we developed criteria for the onset of necking, separately for the flow protocols of step tensile stress, step tensile force, and startup of constant Hencky strain rate. As before, these were derived by studying the linearized dynamics of small heterogeneous perturbations, which are the precursors of a neck, about a state of initially homogeneous extensional flow.…”

Multiple Cracks Propagate Simultaneously in Polymer Liquids in Tension

“…The mode generally occurs on a time scale that allows visual observation. It is generally assumed that an initially axissymmetric filament retains axis symmetry during rupture of this mode [4]. In contrast, our understanding of elastic fracture in polymer liquids is less satisfactory.…”