Calibration of anisotropic yield function by introducing plane strain test instead of equi-biaxial tensile test

To improve the accuracy of forming simulations for sheet metal, the use of material models calibrated by multiaxial material tests is essential. Adequate material models can be calibrated on the basis of the contours of equal plastic work obtained by multiaxial material tests. However, because the tests often require special experimental equipment, they are not widely used by the industry. This paper proposes a methodology for a numerical biaxial tensile test that uses ABAQUS, a popular commercial software package for finite element analysis. In numerical tests, an open-source user-defined material model (UMAT) is used to implement crystal plasticity models. In order to validate our methodology, we performed a numerical biaxial tensile test on a 6000-series aluminum alloy sheet, and the results were compared with those of biaxial tensile tests with a cruciform specimen. The results demonstrated that the proposed numerical biaxial tensile test provides a reasonable prediction of stress-strain curves and the contours of equal plastic work.

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501 Development of biaxial tensile test apparatus with link mechanism

The Proceedings of Conference of Kanto Branch ◽

10.1299/jsmekanto.2012.18.203 ◽

2012 ◽

Vol 2012.18 (0) ◽

pp. 203-204

Author(s):

Shohei IMANO ◽

Susumu TAKAHASHI ◽

Toshihiko KUWABARA

Keyword(s):

Tensile Test ◽

Test Apparatus ◽

Biaxial Tensile Test ◽

Biaxial Tensile ◽

Link Mechanism

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Identification of Anisotropic Yield Criterion Parameters from a Single Biaxial Tensile Test

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.611-612.1710 ◽

2014 ◽

Vol 611-612 ◽

pp. 1710-1717 ◽

Cited By ~ 2

Author(s):

Shun Ying Zhang ◽

Lionel Leotoing ◽

Dominique Guines ◽

Sandrine Thuillier

Keyword(s):

Tensile Test ◽

Yield Criterion ◽

Biaxial Test ◽

Anisotropic Behavior ◽

Yield Model ◽

Plane Stress Condition ◽

Cruciform Specimen ◽

Biaxial Tensile Test ◽

Biaxial Tensile ◽

Strain Paths

The present work deals with the calibration strategy of yield functions used to describe the plastic anisotropic behavior of metallic sheets. In this paper, Bron and Besson yield criterion is used to model the plastic anisotropic behavior of AA5086 sheets. This yield model is flexible enough since the anisotropy is represented by 12 parameters (4 isotropic parameters and 8 anisotropic parameters in plane stress condition) in the form of two linear fourth order transformation tensors. The parameters of this anisotropic yield model have been identified from a single dedicated cross biaxial tensile test. It is shown, from finite element simulations, that the strain distribution in the center of the cruciform specimen is significantly dependent on the yield criterion. Moreover, this cross biaxial test involves a large range of strain paths in the center of the specimen. The calibration stage is performed by means of an optimization procedure minimizing the gap between experimental and numerical values of the principal strains along a specified path in the gauge area of the cruciform specimen. It is shown that the material parameters of Bron and Besson anisotropic yield model can be determined accurately by a unique biaxial tensile test.

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