An Analysis of Shear Localization During Bending of a Polycrystalline Sheet

1992 ◽  
Vol 59 (3) ◽  
pp. 491-496 ◽  
Author(s):  
R. Becker
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Constitutive Model ◽  
Strain Localization ◽  
Texture Evolution ◽  
Rate Sensitivity ◽  
Shear Localization ◽  
Pure Bending ◽  
Stiffness Matrices ◽  
Localized Plastic Deformation

The development of shear localization in a polycrystalline sheet subject to pure bending is analyzed numerically using a slip-based constitutive model. The material response at each finite element integration point is determined by averaging the stiffness matrices from differently oriented FCC crystals. The effects of texture evolution, hardening, and strain-rate sensitivity are incorporated. The model predicts localized plastic deformation at both the tensile and the compressive surfaces of the sheet during bending. Comparison of the numerical results with a section of the bent sheet indicates that strain localization is predicted at the appropriate strain levels and orientations.

MULTI-SCALE FINITE ELEMENT SIMULATION OF SEVERE PLASTIC DEFORMATION

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1621-1626
Author(s):  
HYOUNG SEOP KIM
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Severe Plastic Deformation ◽  
Constitutive Model ◽  
Dislocation Cell ◽  
Ultrafine Grain ◽  
Angular Pressing ◽  
Element Simulation ◽  
Ultrafine Grain Size ◽  
Ultrafine Grained

The technique of severe plastic deformation (SPD) enables one to produce metals and alloys with an ultrafine grain size of about 100 nm and less. As the mechanical properties of such ultrafine grained materials are governed by the plastic deformation during the SPD process, the understanding of the stress and strain development in a workpiece is very important for optimizing the SPD process design and for microstructural control. The objectives of this work is to present a constitutive model based on the dislocation density and dislocation cell evolution for large plastic strains as applied to equal channel angular pressing (ECAP). This paper briefly introduces the constitutive model and presents the results obtained with this model for ECAP by the finite element method.

Texture–Property Relationships in Aluminum Alloys: Simulations and Experiments

2019 ◽  
Author(s):  
Dierk Raabe
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Aluminum Alloys ◽  
Cellular Automata ◽  
Texture Evolution ◽  
Plastic Anisotropy ◽  
Constitutive Laws ◽  
Texture Property ◽  
Forming Simulations

Aluminum alloys provide a huge and increasing application spectrum for formed and cast products. This article texture and anisotropy of aluminum alloys. Topics covered include: experimental determination of surface strains, nanotextures and microtextures, constitutive laws for crystal plasticity finite element simulations and cellular automata for recrystallization, microscopic aspects of texture evolution during plastic deformation and recrystallization, relationship between texture, microstructure and surface properties, integration anisotropy into metal-forming simulations, and crystallographic approximation elastic-plastic anisotropy.

scholarly journals Evolution of Texture and Yield Locus of AISI 409 Ferritic Stainless Steel

1993 ◽  
Vol 21 (4) ◽  
pp. 207-217 ◽  
Author(s):  
N. Mingolo ◽  
A. Pochettino ◽  
C. Vial-Edwards
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Strain Rate ◽  
Strain Hardening ◽  
Ferritic Stainless Steel ◽  
Texture Evolution ◽  
Rate Sensitivity ◽  
Yield Locus ◽  
Slip Systems ◽  
Hardening Process

The evolution of texture and yield locus of AISI 409 ferritic stainless steel under different deformation paths was analyzed.Texture evolution with plastic deformation was predicted by two models: Taylor (TPG), assuming pencil glide in {hkl}〈111〉 slip systems and Viscoplastic under the relaxed constraint assumption (VRC), considering the following slip systems: {110}〈111〉, {112}〈111〉, and {123}〈111〉, selected according to a strain rate sensitivity law. TPG model tends to predict some stronger developments of texture than the VRC model.Predictions of stress–strain curves along different loading paths with TPG and VRC models were very close to experimental results. Texture evolution did not have a significant effect to modify the rate and the isotropy of the strain hardening process of AISI 409 ferritic stainless steel.

A Crystallographic Model for Nickel Base Single Crystal Alloys

1988 ◽  
Vol 55 (2) ◽  
pp. 325-331 ◽  
Author(s):  
L. T. Dame ◽  
D. C. Stouffer
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Single Crystal ◽  
Three Dimensional ◽  
Rate Sensitivity ◽  
Mechanical Analysis ◽  
Orientation Dependence ◽  
Finite Element Code ◽  
Nickel Base ◽  
Octahedral Slip

The purpose of this research is to develop a tool for the mechanical analysis of nickel-base single-crystal superalloys, specifically Rene N4, used in gas turbine engine components. This objective is achieved by developing a rate-dependent anisotropic constitutive model and implementing it in a nonlinear three-dimensional finite-element code. The constitutive model is developed from metallurgical concepts utilizing a crystallographic approach. An extension of Schmid’s law is combined with the Bodner-Partom equations to model the inelastic tension/compression asymmetry and orientation-dependence in octahedral slip. Schmid’s law is used to approximate the inelastic response of the material in cube slip. The constitutive equations model the tensile behavior, creep response and strain-rate sensitivity of the single-crystal superalloys. Methods for deriving the material constants from standard tests are also discussed. The model is implemented in a finite-element code, and the computed and experimental results are compared for several orientations and loading conditions.

IMPLICATIONS OF A CONSTITUTIVE MODEL FOR STRAIN LOCALIZATION

1988 ◽  
Vol 49 (C3) ◽  
pp. C3-489-C3-496
Author(s):  
B. D. COLEMAN ◽  
M. L. HODGDON
Keyword(s):  
Constitutive Model ◽  
Strain Localization
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