Approximate yield criteria for anisotropic porous ductile sheet metals

Liao, K.-C.; Pan, Jwo; Tang, S. C.

doi:10.1016/s0167-6636(97)00033-1

Cited by 95 publications

(69 citation statements)

References 17 publications

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“…Appendix A. Qualitative analysis of the crystal orientation dependence of the void growth rate Following the work by Liao et al (1997), Benzerga and Besson (2001) proposed an extension of the Gurson model in terms of a constitutive model for porous plastically deforming solids involving a spherical void growing within a matrix described by the Hill plastic anisotropy criterion. In the Hill model, the effective stress writes…”

mentioning

confidence: 99%

Void growth and coalescence in single crystals

Sampath

Tekoğlu

Scheyvaerts

et al. 2010

International Journal of Solids and Structures

128

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a b s t r a c tVoid growth and coalescence in single crystals are investigated using crystal plasticity based 3D finite element calculations. A unit cell involving a single spherical void and fully periodic boundary conditions is deformed under constant macroscopic stress triaxiality. Simulations are performed for different values of the stress triaxiality, for different crystal orientations, and for low and high work-hardening capacity. Under low stress triaxiality, the void shape evolution, void growth, and strain at the onset of coalescence are strongly dependent on the crystal orientation, while under high stress triaxiality, only the void growth rate is affected by the crystal orientation. These effects lead to significant variations in the ductility defined as the strain at the onset of coalescence. An attempt is made to predict the onset of coalescence using two different versions of the Thomason void coalescence criterion, initially developed in the framework of isotropic perfect plasticity. The first version is based on a mean effective yield stress of the matrix and involves a fitting parameter to properly take into account material strain hardening. The second version of the Thomason criterion is based on a local value of the effective yield stress in the ligament between the voids, with no fitting parameter. The first version is accurate to within 20% relative error for most cases, and often more accurate. The second version provides the same level of accuracy except for one crystal orientation. Such a predictive coalescence criterion constitutes an important ingredient towards the development of a full constitutive model for porous single crystals.

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confidence: 99%

Void growth and coalescence in single crystals

Sampath

Tekoğlu

Scheyvaerts

et al. 2010

International Journal of Solids and Structures

128

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“…(3) is in agreement with the yield function of Doege (1997) in a=2 for an anisotropic voided material. Liao, et al (1997) investigated the yield surface of anisotropic material and the void growth during strain using Hill's non-quadratic anisotropic yield criterion. According to the normality rule of the plastic strain vector for the yield surface, the principal plastic strain increments are derived based on the partial differential of the yield function with respect to the stresses, respectively.…”

Section: Theoretical Analysismentioning

confidence: 99%

Approximate yield criterion for voided anisotropic ductile materials

Kim

Won

Kim

et al. 2001

KSME International Journal

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1349As most fractures of ductile materials in metal forming processes occurred due to the results of evolution of internal damage -void nucleation, growth and coalescence. In this paper, an approximate yield criterion for voided (porous) anisotropic ductile materials is developed. The proposed approximate yield function is based on Gurson's yield function in conjunction with the Hosford's non-quadratic anisotropic yield criterion in order to consider the characteristic of anisotropic properties of matrix material. The associated flow rules are presented and the laws governing void growth with strain are derived. Using the proposed model void growth of an anisotropic sheet under biaxial tensile loading and its effect on sheet metal formability are investigated. The yield surface of voided anisotropic sheet and void growth with strain are predicted and compared with the experimental results.

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“…But after rolling process, the sheet metal usually displays plasticity anisotropy. Basing on Hill'48 quadratic yield criterion, Liao et al [8] developed an approximate yield criterion for anisotropic porous sheet metal under plane stress condition. Doege [9] proposed an anisotropic GTN model to simulate the deepdrawing process.…”

Section: Introductionmentioning

confidence: 99%

Comparison of GTN damage models for sheet metal forming

Chen

Dong

2008

J. Shanghai Jiaotong Univ. (Sci.)

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The Gurson-Tvergaard-Needleman (GTN) damage model was developed basing on anisotropic yield criterion to predict the damage evolution for anisotropic voided ductile materials. Hill's quadratic anisotropic yield criterion (1948) and Barlat's 3-component anisotropic yield criterion (1989) were used to describe the anisotropy of the matrix. User defined subroutines were developed using the above models. Taking the benchmark of NUMISHEET'93 square cup deep drawing as an example, the effect of matrix plastic anisotropy on a ductile material was studied. The predicted result by Barlat'89-GTN model has a better agreement with the experimental data than that by Hill'48-GTN and the original GTN model.

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Approximate yield criteria for anisotropic porous ductile sheet metals

Cited by 95 publications

References 17 publications

Void growth and coalescence in single crystals

Void growth and coalescence in single crystals

Approximate yield criterion for voided anisotropic ductile materials

Comparison of GTN damage models for sheet metal forming

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