Journal ArticleDOI
Influence of voids on shear band instabilities under plane strain conditions
TLDR
In this paper, the effect of microscopic voids on the failure mechanism of a ductile material is investigated by considering an elastic-plastic medium containing a boubly periodic array of circular cylindrical voids.Abstract:
The effect of microscopic voids on the failure mechanism of a ductile material is investigated by considering an elastic-plastic medium containing a boubly periodic array of circular cylindrical voids. For this voided material under uniaxial or biaxial plane strain tension the state of stresses and deformations is determined numerically. Bifurcation away from the fundamental state of deformation is analysed with special interest in a repetitive pattern that represents the state of deformation inside a shear band. Both in the fundamental state and in the bifurcation analysis the interaction between voids and the details of the stress distribution around voids are fully accounted for. Comparison is made with the shear band instabilities predicted by a continuum model of a ductile porous medium. Based on the numerical results an adjustment is suggested for the approximate yield condition in this model of dilatant, pressure sensitive plastic behaviour.read more
Citations
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Journal ArticleDOI
Analysis of the cup-cone fracture in a round tensile bar
Viggo Tvergaard,Alan Needleman +1 more
TL;DR: In this article, a set of elastic-plastic constitutive relations that account for the nucleation and growth of micro-voids is used to model the failure of a round tensile test specimen.
Journal ArticleDOI
A continuous damage mechanics model for ductile fracture
TL;DR: In this paper, a model of isotropic ductile plastic damage based on a continuum damage variable, on the effective stress concept and on thermodynamics is derived, showing a large influence of triaxiality by means of a damage equivalent stress.
Journal ArticleDOI
On localization in ductile materials containing spherical voids
TL;DR: In this article, an axisymmetric numerical model and a set of approximate constitutive equations for a voided material suggested by Gurson were used to analyse bifurcation into a localized mode.
Book ChapterDOI
Material Failure by Void Growth to Coalescence
TL;DR: In this paper, a convected coordinate formulation of the field equations is used to describe the material failure by coalescence of microscopic voids, and a detailed micromechanical study of shear band bifurcation that accounts for the interaction between neighboring voids and the strongly nonhomogeneous stress distributions around each void has been carried out, and also elaborated in this chapter.
Journal ArticleDOI
Modification of the Gurson Model for shear failure
Ken Nahshon,John W. Hutchinson +1 more
TL;DR: In this paper, an extension of the Gurson model is proposed that incorporates damage growth under low triaxiality straining for shear-dominated states, which can be used to characterize important growth and coalescence features.
References
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Journal ArticleDOI
Continuum Theory of Ductile Rupture by Void Nucleation and Growth: Part I—Yield Criteria and Flow Rules for Porous Ductile Media
Journal ArticleDOI
On the ductile enlargement of voids in triaxial stress fields
James R. Rice,D.M. Tracey +1 more
TL;DR: In this article, a variational principle is established to characterize the flow field in an elastically rigid and incompressible plastic material containing an internal void or voids, and an approximate Rayleigh-Ritz procedure is developed and applied to the enlargement of an isolated spherical void in a nonhardening material.
Journal ArticleDOI
Conditions for the localization of deformation in pressure-sensitive dilatant materials
John W. Rudnicki,James R. Rice +1 more
TL;DR: In this paper, the authors investigated the hypothesis that localization of deformation into a shear band may be considered a result of an instability in the constitutive description of homogeneous deformation.
Journal ArticleDOI
A general theory of uniqueness and stability in elastic-plastic solids
TL;DR: A sufficient condition for uniqueness of the boundary-value problem set by given velocities on a part of the surface of a body and given nominal traction-rates on the remainder is established in this paper.