Microstructural effects in aqueous foam fracture

Peter S. Stewart, Stephen H. Davis, Sascha Hilgenfeldt

Research output: Contribution to journalArticle

Abstract

We examine the fracture of a quasi-two-dimensional surfactant-laden aqueous foam under an applied driving pressure, using a network modelling approach developed for metallic foams by Stewart & Davis (J. Rheol., vol. 56, 2012, p. 543). In agreement with experiments, we observe two distinct mechanisms of failure analogous to those observed in a crystalline solid: a slow ductile mode when the driving pressure is applied slowly, where the void propagates as bubbles interchange neighbours through the T1 process; and a rapid brittle mode for faster application of pressures, where the void advances by successive rupture of liquid films driven by Rayleigh-Taylor instability. The simulations allow detailed insight into the mechanics of the fracturing medium and the role of its microstructure. In particular, we examine the stress distribution around the crack tip and investigate how brittle fracture localizes into a single line of breakages. We also confirm that pre-existing microstructural defects can alter the course of fracture.

Original languageEnglish (US)
Pages (from-to)425-461
Number of pages37
JournalJournal of Fluid Mechanics
Volume785
DOIs
StatePublished - Nov 23 2015

Fingerprint

foams
Foams
voids
Taylor instability
fracturing
crack tips
Brittle fracture
Interchanges
Liquid films
Crack tips
stress distribution
Stress concentration
Mechanics
Surface active agents
bubbles
surfactants
Crystalline materials
Defects
microstructure
Microstructure

Keywords

  • fingering instability
  • foams
  • interfacial flows (free surface)

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Condensed Matter Physics

Cite this

Microstructural effects in aqueous foam fracture. / Stewart, Peter S.; Davis, Stephen H.; Hilgenfeldt, Sascha.

In: Journal of Fluid Mechanics, Vol. 785, 23.11.2015, p. 425-461.

Research output: Contribution to journalArticle

Stewart, Peter S. ; Davis, Stephen H. ; Hilgenfeldt, Sascha. / Microstructural effects in aqueous foam fracture. In: Journal of Fluid Mechanics. 2015 ; Vol. 785. pp. 425-461.
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