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

Hoyle, David M.; Fielding, Suzanne M.

Abstract

We study the instability to necking of an initially cylindrical filament of soft glassy material subject to extensional stretching. By numerical simulation of the soft glassy rheology model and a simplified fluidity model, and by analytical predictions within a highly generic toy description, we show that the mode of instability is set by the age of the sample relative to the inverse of the applied extensional strain rate. Young samples neck gradually via a liquidlike mode, the onset of which is determined by both the elastic loading and plastic relaxation terms in the stress constitutive equation. Older samples fail at smaller draw ratios via a more rapid mode, the onset of which is determined only by the solidlike elastic loading terms (though plastic effects arise later, once appreciable necking develops). We show this solidlike mode to be the counterpart, for elastoplastic materials, of the Considère mode of necking in strain-rate-independent solids.

Citation

Hoyle, D. M., & Fielding, S. M. (2015). Age-Dependent Modes of Extensional Necking Instability in Soft Glassy Materials. Physical Review Letters, 114(15), Article 158301. https://doi.org/10.1103/physrevlett.114.158301

• Journal Article Type: Article
• Acceptance Date: Apr 1, 2015
• Online Publication Date: Apr 15, 2015
• Publication Date: Apr 17, 2015
• Deposit Date: Apr 29, 2015
• Publicly Available Date: May 1, 2015
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 114
• Issue: 15
• Article Number: 158301
• DOI: https://doi.org/10.1103/physrevlett.114.158301
• Public URL: https://durham-repository.worktribe.com/output/1409523
• Related Public URLs: http://arxiv.org/abs/1412.2959