scholarly journals Localized Necking in Elastomer-Supported Metal Layers: Impact of Kinematic Hardening

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Mohamed Ben Bettaieb ◽  
Farid Abed-Meraim
Keyword(s):  
Parametric Study ◽  
Strain Path ◽  
Kinematic Hardening ◽  
Metal Layer ◽  
Initial Imperfection ◽  
Flow Theory ◽  
Rigid Plastic ◽  
Localized Necking ◽  
Metal Sheets ◽  
Metal Layers

This paper deals with localized necking in stretched metal sheets using the initial imperfection approach. The first objective is to study the effect of kinematic hardening on the formability of a freestanding metal layer. To this end, the behavior of the metal layer is assumed to follow the rigid-plastic rate-independent flow theory. The isotropic (respectively, kinematic) hardening of this metal is modeled by the Hollomon (respectively, Prager) law. A parametric study is carried out in order to investigate the effect of kinematic hardening on the formability limits. It is shown that the effect of kinematic hardening on the ductility limit is noticeably different depending on the strain path considered. The second aim of this paper is to analyze the effect of an elastomer substrate, perfectly bonded to the metal layer, on the formability of the whole bilayer. It is found that the addition of an elastomer layer substantially enhances the formability of the bilayer, in agreement with earlier studies.

Analytical Solutions for Circular Bars Subjected to Large Strain Plastic Torsion

1990 ◽  
Vol 57 (2) ◽  
pp. 298-306 ◽  
Author(s):  
K. W. Neale ◽  
S. C. Shrivastava
Keyword(s):  
Closed Form ◽  
Analytical Solutions ◽  
Large Strain ◽  
Kinematic Hardening ◽  
Flow Theory ◽  
Constitutive Laws ◽  
Isotropic Hardening ◽  
Large Strains ◽  
Inelastic Behavior ◽  
Rate Dependent

The inelastic behavior of solid circular bars twisted to arbitrarily large strains is considered. Various phenomenological constitutive laws currently employed to model finite strain inelastic behavior are shown to lead to closed-form analytical solutions for torsion. These include rate-independent elastic-plastic isotropic hardening J2 flow theory of plasticity, various kinematic hardening models of flow theory, and both hypoelastic and hyperelastic formulations of J2 deformation theory. Certain rate-dependent inelastic laws, including creep and strain-rate sensitivity models, also permit the development of closed-form solutions. The derivation of these solutions is presented as well as numerous applications to a wide variety of time-independent and rate-dependent plastic constitutive laws.

scholarly journals Experimental and Numerical Study of the Effects of the Reversal Hot Rolling Conditions on the Recrystallization Behavior of Austenite Model Alloys

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Krzysztof Muszka ◽  
Mateusz Sitko ◽  
Paulina Lisiecka-Graca ◽  
Thomas Simm ◽  
Eric Palmiere ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Hot Rolling ◽  
Strain Path ◽  
Physical Simulation ◽  
Numerical Study ◽  
Kinematic Hardening ◽  
Process Window ◽  
Recrystallization Behavior ◽  
Full Field ◽  
Strain Reversal

The experimental and numerical study of the effects of the recrystallization behavior of austenite model alloys during hot plate rolling on reverse rolling is the main goal of the paper. The computer models that are currently applied for simulation of reverse rolling are not strain-path-sensitive, thus leading to overestimation of the processing parameters outside the accepted process window (e.g., deformation in the partial austenite recrystallization region). Therefore, in this work, a particular focus is put on the investigation of strain path effects that occur during hot rolling and their influence on the microstructure evolution and mechanical properties of microalloyed austenite. Both experimental and numerical techniques are employed in this study, taking advantage of the integrated computational material engineering concept. The combined isotropic–kinematic hardening model is used for the macroscale predictions to take into account softening effects due to strain reversal. The macroscale model is additionally enriched with the full-field microstructure evolution model within the cellular automata framework. Examples of obtained results, highlighting the role of the strain reversal on the microstructural response, are presented within the paper. The combination of the physical simulation of austenitic model alloys and computer modeling provided new insights into optimization of the processing routes of advanced high-strength steels (AHSS).

Studies of Elastic-Plastic Instabilities

1999 ◽  
Vol 66 (1) ◽  
pp. 3-9 ◽  
Author(s):  
V. Tvergaard
Keyword(s):  
Shear Band ◽  
Plastic Flow ◽  
Continuum Mechanics ◽  
Shear Band Formation ◽  
Band Formation ◽  
Elastic Plastic ◽  
Localized Necking ◽  
Focus On Results ◽  
Metal Sheets ◽  
Bifurcation Behavior

Analyses of plastic instabilities are reviewed, with focus on results in structural mechanics as well as continuum mechanics. First the basic theories for bifurcation and post-bifurcation behavior are briefly presented. Then, localization of plastic flow is discussed, including shear band formation in solids, localized necking in biaxially stretched metal sheets, and the analogous phenomenon of buckling localization in structures. Also some recent results for cavitation instabilities in elastic-plastic solids are reviewed.

Cyclic Plasticity for Nonproportional Paths: Part 2—Comparison With Predictions of Three Incremental Plasticity Models

1978 ◽  
Vol 100 (1) ◽  
pp. 104-111 ◽  
Author(s):  
H. S. Lamba ◽  
O. M. Sidebottom
Keyword(s):  
Cyclic Loading ◽  
Material Property ◽  
Yield Surface ◽  
Strain Path ◽  
Kinematic Hardening ◽  
Cyclic Plasticity ◽  
Limit Surface ◽  
Hardening Rule ◽  
Hardening Models ◽  
Hardening Rules

Experiments that demonstrate the basic quantitative and qualitative aspects of the cyclic plasticity of metals are presented in Part 1. Three incremental plasticity kinematic hardening models of prominence are based on the Prager, Ziegler, and Mroz hardening rules, of which the former two have been more frequently used than the latter. For a specimen previously fully stabilized by out of phase cyclic loading the results of a subsequent cyclic nonproportional strain path experiment are compared to the predictions of the above models. A formulation employing a Tresca yield surface translating inside a Tresca limit surface according to the Mroz hardening rule gives excellent predictions and also demonstrates the erasure of memory material property.

scholarly journals Inverse Strategies for Identifying the Parameters of Constitutive Laws of Metal Sheets

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
P. A. Prates ◽  
A. F. G. Pereira ◽  
N. A. Sakharova ◽  
M. C. Oliveira ◽  
J. V. Fernandes
Keyword(s):  
Finite Element ◽  
Cost Function ◽  
Optimization Algorithm ◽  
Yield Criterion ◽  
Kinematic Hardening ◽  
Constitutive Laws ◽  
Constitutive Law ◽  
Identification Procedure ◽  
Metal Sheets ◽  
The Cost

This article is a review regarding recently developed inverse strategies coupled with finite element simulations for the identification of the parameters of constitutive laws that describe the plastic behaviour of metal sheets. It highlights that the identification procedure is dictated by the loading conditions, the geometry of the sample, the type of experimental results selected for the analysis, the cost function, and optimization algorithm used. Also, the type of constitutive law (isotropic and/or kinematic hardening laws and/or anisotropic yield criterion), whose parameters are intended to be identified, affects the whole identification procedure.

Corotational Rates for Kinematic Hardening at Large Plastic Deformations

1983 ◽  
Vol 50 (3) ◽  
pp. 561-565 ◽  
Author(s):  
Y. F. Dafalias
Keyword(s):  
Simple Shear ◽  
Plastic Material ◽  
Kinematic Hardening ◽  
Back Stress ◽  
Analytical Form ◽  
Rigid Plastic ◽  
Plastic Deformations ◽  
Novel Approach ◽  
Rigid Plastic Material ◽  
Large Plastic Deformations

To illustate the effect of the choice of corotational rates at large plastic deformations, expressions for the stresses developing in large simple shear are obtained in closed analytical form under the assumptions of a rigid-plastic material response and a Mises type isotropically and kinematically hardening constitutive model for two different corotational rates applied to the stress and the back-stress tensors. The observed difference in the simple shear response and the relative merits of the foregoing and other corotational rates are discussed, and a novel approach is proposed based on Mandel’ work and the representation theorem for isotropic second-order antisymmetric tensor valued functions.

The Influence of Metal Layer on the Differential Transformer Displacement Sensor

2011 ◽  
Vol 121-126 ◽  
pp. 3594-3601
Author(s):  
Chao Wu Jin ◽  
Long Xiang Xu ◽  
Qiu Ping Fan ◽  
Yi Li Zhu
Keyword(s):  
Metal Layer ◽  
Cutoff Frequency ◽  
External Environment ◽  
Displacement Sensor ◽  
Impact Factors ◽  
Active Magnetic Bearings ◽  
Test Bed ◽  
Amb System ◽  
The Impact ◽  
Metal Layers

For some special active magnetic bearings (AMBs) application occasions that demand the rotor isolated from external environment, especially when a metal layer is added, other sensors besides differential transformer displacement sensor (DTDS) can not used to detect the rotor displacements. Before being used, the impact factors and relevant extents on the DTDS performances are analyzed on the basis of magnetic and electrical properties the added metal layer between the DTDS core and the measured object. The DTDS performance with and without metal layers are separately simulated on the platform of MATLAB and ANSOFT. And then the DTDS with metal layers are applied to a five-DOF AMB test bed. The research results show that the sensor sensitivity has decreased 8.18% and cutoff frequency decreased 5%, while the linearity increased 38.7%. Despite of those changes, the rotor can also be stably suspended and rotated at 30 000r/min in the five-DOF AMB system.

Sign in / Sign up

Export Citation Format

Share Document