The cyclic stress-strain properties, hysteresis loop shape, and kinematic hardening of two high-strength bearing steels

1990 ◽  
Vol 21 (2) ◽  
pp. 653-665 ◽  
Author(s):  
G. T. Hahn ◽  
V. Bhargava ◽  
Q. Chen
Keyword(s):  
Hysteresis Loop ◽  
Kinematic Hardening ◽  
High Strength ◽  
Cyclic Stress ◽  
Stress Strain ◽  
Bearing Steels ◽  
Loop Shape

Generation of Cyclic Stress-Strain Curves for Sheet Metals

2000 ◽  
Author(s):  
K. M. Zhao ◽  
J. K. Lee
Keyword(s):  
Constitutive Model ◽  
Kinematic Hardening ◽  
Optimization Procedure ◽  
High Strength ◽  
Cyclic Stress ◽  
Bending Moments ◽  
Sheet Metals ◽  
Stress Strain ◽  
Normal Anisotropy ◽  
Material Parameters

Abstract The main objective of this paper is to generate cyclic stress-strain curves for sheet metals so that the springback can be simulated accurately. Material parameters are identified by an inverse method within a selected constitutive model that represents the hardening behavior of materials subjected to a cyclic loading. Three-point bending tests are conducted on sheet steels (mild steel and high strength steel). Punch stroke, punch load, bending strain and bending angle are measured directly during the tests. Bending moments are then computed from these measured data. Bending moments are also calculated based on a constitutive model. Normal anisotropy and nonlinear isotropic/kinematic hardening are considered. Material parameters are identified by minimizing the normalized error between two bending moments. Micro genetic algorithm is used in the optimization procedure. Stress-strain curves are generated with the material parameters found in this way, which can be used with other plastic models.

Generation of Cyclic Stress-Strain Curves for Sheet Metals

2000 ◽  
Vol 123 (4) ◽  
pp. 391-397 ◽  
Author(s):  
K. M. Zhao ◽  
J. K. Lee
Keyword(s):  
Constitutive Model ◽  
Kinematic Hardening ◽  
Optimization Procedure ◽  
High Strength ◽  
Cyclic Stress ◽  
Bending Moments ◽  
Sheet Metals ◽  
Stress Strain ◽  
Normal Anisotropy ◽  
Material Parameters

The main objective of this paper is to obtain the first few stress-strain loops of sheet metals from reverse loading so that the springback can be simulated accurately. Material parameters are identified by an inverse method within a selected constitutive model that represents the hardening behavior of materials subjected to a cyclic loading. Three-point bending tests are conducted on sheet steels (mild steel and high strength steel). Punch stroke, punch load, bending strain, and bending angle are measured directly during the tests. Bending moments are then computed from these measured data. Bending moments are also calculated based on a constitutive model. Normal anisotropy and nonlinear isotropic/kinematic hardening are considered. Material parameters are identified by minimizing the normalized error between two bending moments. Micro-genetic algorithm is used in the optimization procedure. Stress-strain curves are generated with the material parameters found in this way, which can be used with other plastic models.

Description of Closure of Cyclic Stress-Strain Loop and Ratcheting Based on Y-U Model

2016 ◽  
Vol 725 ◽  
pp. 351-356
Author(s):  
Fusahito Yoshida ◽  
Hiroshi Hamasaki ◽  
Takeshi Uemori
Keyword(s):  
Hysteresis Loop ◽  
Kinematic Hardening ◽  
Cyclic Stress ◽  
Cyclic Plasticity ◽  
Plasticity Model ◽  
Stress Strain ◽  
Additional Material ◽  
Material Parameters ◽  
Hardening Law ◽  
Cyclic Plasticity Model

This paper proposes a cyclic plasticity model to describe the closure of a cyclic stress-strain hysteresis loop based on the Y-U model. In this model, the backstress moves in a cyclic memory surface following a newly proposed kinematic hardening law. For this model just the same Y-U parameters can be used, and no additional material parameters are needed. By using a supplementary rule, this model is also able to describe ratcheting.

scholarly journals Micromechanical Modelling of the Cyclic Deformation Behavior of Martensitic SAE 4150—A Comparison of Different Kinematic Hardening Models

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 368 ◽  
Author(s):  
Benjamin Schäfer ◽  
Xiaochen Song ◽  
Petra Sonnweber-Ribic ◽  
Hamad ul Hassan ◽  
Alexander Hartmaier
Keyword(s):  
Kinematic Hardening ◽  
Three Dimensional ◽  
High Strength ◽  
Element Model ◽  
Calibration Procedure ◽  
Cyclic Stress ◽  
System Level ◽  
Strain Behavior ◽  
Hardening Models ◽  
Mean Stress Relaxation

A fundamental prerequisite for the micromechanical simulation of fatigue is the appropriate modelling of the effective cyclic properties of the considered material. Therefore, kinematic hardening formulations on the slip system level are of crucial importance due to their fundamental relevance in cyclic material modelling. The focus of this study is the comparison of three different kinematic hardening models (Armstrong Frederick, Chaboche, and Ohno–Wang). In this work, investigations are performed on the modelling and prediction of the cyclic stress-strain behavior of the martensitic high-strength steel SAE 4150 for two different total strain ratios (R ε = −1 and R ε = 0). In the first step, a three-dimensional martensitic microstructure model is developed by using multiscale Voronoi tessellations. Based on this martensitic representative volume element, micromechanical simulations are performed by a crystal plasticity finite element model. For the constitutive model calibration, a new multi-objective calibration procedure incorporating a sensitivity analysis as well as an evolutionary algorithm is presented. The numerical results of different kinematic hardening models are compared to experimental data with respect to the appropriate modelling of the Bauschinger effect and the mean stress relaxation behavior at R ε = 0. It is concluded that the Ohno–Wang model is superior to the Armstrong Frederick and Chaboche kinematic hardening model at R ε = −1 as well as at R ε = 0.

Tension-Compression Tests for Springback Prediction of AHS Steel Using the Yoshida-Uemori Model

2017 ◽  
Vol 728 ◽  
pp. 78-84
Author(s):  
Weerapong Julsri ◽  
Surasak Suranuntchai ◽  
Vitoon Uthaisangsuk
Keyword(s):  
Elastic Recovery ◽  
Kinematic Hardening ◽  
High Strength ◽  
Cyclic Stress ◽  
Model Parameters ◽  
Structural Components ◽  
Compression Tests ◽  
Complex Shapes ◽  
Automotive Parts ◽  
Springback Prediction

In sheet metal formingprocess of automotive parts, springback effect is crucial, in particular, foradvanced high strength (AHS) steels. Most structural components of new vehiclesshow very complex shapes that require multi–step forming procedures.Therefore, finite element (FE)simulation has been often used to describe plasticdeformation behavior and springback occurrence of formed metal sheets.Recently, the kinematic hardening Yoshida–Uemorimodel has showed great capability for predicting elastic recovery of material. In this work, the AHSsteel grade JSC780Y wasinvestigated, in which tension–compressiontests were carried out. From resulted cyclic stress–strainresponses, material parameters were identified using different fitting methods.Determined model parameters were firstly verified by using simulations of 1–elementmodel. The most appropriate parameter set was thenobtained. Finally, a Hat-Shape forming test was performed and springback waspredicted and compared with experimental results.

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