Prediction of forming limit curves using an anisotropic yield function with prestrain induced backstress

2002 ◽  
Vol 18 (8) ◽  
pp. 1013-1038 ◽  
Author(s):  
Hong Yao ◽  
Jian Cao
Keyword(s):  
Yield Function ◽  
Forming Limit ◽  
Anisotropic Yield Function ◽  
Forming Limit Curves

scholarly journals Effect of Anisotropic Yield Function Evolution on Estimation of Forming Limit Diagram

2017 ◽  
Vol 896 ◽  
pp. 012015
Author(s):  
K Bandyopadhyay ◽  
S Basak ◽  
H J Choi ◽  
S K Panda ◽  
M G Lee
Keyword(s):  
Forming Limit Diagram ◽  
Yield Function ◽  
Forming Limit ◽  
Anisotropic Yield Function

Limit Strains Analysis of Advanced High Strength Steels Sheets Based on Surface Roughness Measurements

2018 ◽  
Vol 930 ◽  
pp. 349-355
Author(s):  
Lílian Barros da Silveira ◽  
Luciano Pessanha Moreira ◽  
Ladario da Silva ◽  
Rafael Oliveira Santos ◽  
Fabiane Roberta Freitas da Silva ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Strength Steels ◽  
High Strength ◽  
Yield Function ◽  
Forming Limit ◽  
Dual Phase ◽  
Dual Phase Steels ◽  
Advanced High Strength Steels ◽  
Anisotropic Yield Function ◽  
Localization Model

The limit strains of dual-phase steels DP600 and 800 were evaluated in this work with a localization model formulated in plane-stress conditions using elasto-plastic constitutive equations. In this model, a geometrical imperfection parameter is defined from the sheet nominal thickness, initial ferrite grain size and average surface roughness. The proposed identification procedure provided a more physically meaning for this parameter and at best more conservative predictions in the drawing Forming Limit Curve (FLC) range of both investigated dual-phase steels. Nevertheless, the corresponding limit strains in the biaxial stretching region are underestimated with the present theoretical model. Thus, more detailed anisotropic yield function and hardening descriptions must be implemented to improve the accuracy of the FLC prediction of advanced high strength steels.

Effect of the Constitutive Law on the Accuracy of Prediction of the Forming Limit Curves

2012 ◽  
Vol 504-506 ◽  
pp. 77-82 ◽  
Author(s):  
Liana Paraianu ◽  
Dan Sorin Comsa ◽  
Ioan Pavel Nicodim ◽  
Ioan Ciobanu ◽  
Dorel Banabic
Keyword(s):  
Sheet Metal ◽  
Mechanical Response ◽  
Yield Criterion ◽  
Plastic Anisotropy ◽  
Equivalent Stress ◽  
Point Of View ◽  
Constitutive Law ◽  
Forming Limit ◽  
Accuracy Of Prediction ◽  
Forming Limit Curves

The accuracy of the forming limit curves predicted by the Marciniak-Kuczynski model depends on the type and flexibility of the constitutive equations used to describe the mechanical response of the sheet metal. From this point of view, the yield criterion has the most significant influence. The paper presents a comparative analysis referring to the quality of the forming limit curves predicted by the Marciniak-Kuczynski model for the case when the plastic anisotropy of a DC04 sheet metal is described by the BBC2005 yield criterion. The coefficients included in the expression of the BBC2005 equivalent stress are evaluated using different identification strategies (with 4, 6, 7, and 8 mechanical parameters). The forming limit curves predicted by the Marciniak-Kuczynski model in each of the cases previously mentioned are compared with experimental data.

Effect of Material Frame Rotation on the Hardening of an Anisotropic Material in Simple Shear Tests

2018 ◽  
Vol 85 (12) ◽  
Author(s):  
Kelin Chen ◽  
Stelios Kyriakides ◽  
Martin Scales
Keyword(s):  
Simple Shear ◽  
Plastic Anisotropy ◽  
Yield Function ◽  
Strain Response ◽  
Shear Tests ◽  
Stress Strain ◽  
Anisotropic Yield Function ◽  
Torsion Experiment ◽  
Thin Walled Tube ◽  
Material Frame

The shear stress–strain response of an aluminum alloy is measured to a shear strain of the order of one using a pure torsion experiment on a thin-walled tube. The material exhibits plastic anisotropy that is established through a separate set of biaxial experiments on the same tube stock. The results are used to calibrate Hill's quadratic anisotropic yield function. It is shown that because in simple shear the material axes rotate during deformation, this anisotropy progressively reduces the material tangent modulus. A parametric study demonstrates that the stress–strain response extracted from a simple shear test can be influenced significantly by the anisotropy parameters. It is thus concluded that the material axes rotation inherent to simple shear tests must be included in the analysis of such experiments when the material exhibits anisotropy.

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