Influence of porosity on cavitation instability predictions for elastic-plastic solids

Viggo Tvergaard, G. Vadillo

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Cavitation instabilities have been found for a single void in a ductile metal stressed under high triaxiality conditions. Here, the possibility of unstable cavity growth is studied for a metal containing many voids. The central cavity is discretely represented, while the surrounding voids are represented by a porous ductile material model in terms of a field quantity that specifies the variation of the void volume fraction in the surrounding metal. As the central void grows, the surrounding void volume fractions increase in nonuniform fields, where the strains grow very large near the void surface, while the high stress levels are reached at some distance from the void, and the interaction of these stress and strain fields determines the porosity evolution. In some cases analysed, the porosity is present initially in the metal matrix, while in other cases voids nucleate gradually during the deformation process. It is found that interaction with the neighbouring voids reduces the critical stress for unstable cavity growth.
Original languageEnglish
JournalInternational Journal of Mechanical Sciences
Volume49
Issue number2
Pages (from-to)210-216
ISSN0020-7403
DOIs
Publication statusPublished - 2007

Keywords

  • Plasticity
  • Instability
  • Finite strains
  • Ductile fracture

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