The effects of rate sensitivity and plastic potential surface curvature on plastic flow localization in porous solids
نویسنده
چکیده
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 tension, and localized necking in biaxially stretched sheets are analyzed by using the present material model. The results illustrate the interactions of the effects of void nucleation and growth, material rate sensitivity and plastic potential surface curvature on plastic flow localization. The effects of nonproportional straining paths on localized necking in thin sheets are also demonstrated.
منابع مشابه
A Sub Loading Surface Multilaminate Model for Elastic-Plastic Porous Media
A framework for development of constitutive models based on semi-micromechanical aspects of plasticity is proposed. The resulting of this model for material employed friction type failure criterion, sub-loading surface, and associated flow rule. This model is capable of predicting effects of the rotation of principal stress/strain axes and consequent plastic flow, induced anisotropy of strength...
متن کاملEffects of Nonlocal Damage in Porous Plastic Solids
A nonlocal constitutive formulation for a porous ductile material is investigated, in which delocalizadon relates to the damage mechanism. An elastic-viscoplastic material model is used, with delocalization incorporated in terms of an integral condition on the rate of increase of the void volume fraction. Two model problems are analysed to study the effect of including this material length, one...
متن کاملFinite element analysis of elastic-plastic solids under Vickers indentation: surface deformation
Finite element modeling has been used to study the development of surface deformation during indentation with a Vickers indenter. A wide range of materials with different elastic modulus and yield stresses are examined. Results show that in a pyramidal indentation process, for a perfectly plastic material, sinking-in during loading can change to pile-up in unloading. This phenomenon depends on ...
متن کاملPlastic deformation analysis in parallel tubular channel angular pressing (PTCAP)
Parallel tubular channel angular pressing (PTCAP) process is a novel recently developed severe plastic deformation technique for fabrication of ultrafine grained (UFG) metallic tubes. This new process consists of two half cycles and is affected by several parameters such as channel angles, deformation ratio and curvature angles. In this paper, the effects of these parameters on the plastic defo...
متن کاملGrain Size Effect on the Hot Deformation Processing Map of AISI 304 Austenitic Stainless Steel
In this study, the hot deformation processing map of AISI 304 austenitic stainless steel in two initial grain sizes of 15 and 40 μm was investigated. For this purpose, cylindrical samples were used in the hot compression test at the temperature range of 950-1100 °C and the strain rate of 0.005-0.5% s-1. At first, the relationship between the peak stress and Zener-Hollomon parameter w...
متن کامل