SIJMMARY BY USING a simplified constitutive model of a pointed vertex on subsequent yield loci, namely, such that the equations of deformation-theory of rigid-plastic solids apply for fully-active stress increments, the onset of localized necking under biaxial stretching has been predicted. The predictions agree reasonably well with reported experimental observations. Since localized necking un...

The plastic stability and ductile rupture under evolution of cavity-damage and local strength inhomogeneities are examined theoretically for uniaxial tension. Analytical solutions are derived for that arbitrary strain-induced formations modified to stress-triaxiality evolution during necking. With increasing rate of damage formation necking is enhanced and ductility as well as load drop reduces...

Plastic flow localization in porous elastic-viscoplastic solids is analyzed with an emphasis on the effects of material rate sensitivity and plastic potential surface curvature. The effect of rate sensitivity is included in a material model that accounts for a change of yield surface curvature in a rate-insensitive porous ductile solid. Shear band formation under plane strain and axisymmetric t...

In Incremental Sheet Forming (ISF) strains can be obtained well above the Forming Limit Curve (FLC) that is applicable to common sheet forming operations like deep drawing and stretching. This paper presents an overview of mechanisms that have been suggested to explain the enhanced formability. The difference between fracture limit and necking limit in sheet metal forming is discussed. The neck...

Dimensional reduction is applied to derive a one-dimensional energy functional governing tensile necking localization in a family of initially uniform prismatic solids, including as particular cases rectilinear blocks in plane strain and cylindrical bars undergoing axisymmetric deformations. The energy functional depends on both the axial stretch and its gradient. The coefficient of the gradien...

Abstract Necking is a very common phenomenon in uniaxial tensile experiments. It particularly prominent materials with high-stress levels. can be considered deformation destabilization or localized concentration of deformation. The occurrence this lead to the failure stress-strain curve material. Therefore, paper will examine problem correction tension for high levels yield stress. Due class ma...

Periodic bifurcation modes that occur in ductile multilayered plates or sheets stretched in plane strain tension are analyzed to reveal whether necks are likely to localize at the scale of the thickness of individual layers or at the scale of the full thickness of the multilayer. The energy dissipated in tearing a ductile multilayer scales with the extent of the localized thinning region in the...