Effects of biaxial tensile mechanical properties and non-integer exponent on description accuracy of anisotropic yield behavior. (15th December 2021)

• Record Type: Journal Article
• Authors: Du, Kai; Huang, Shaohui; Shi, Minghao; Li, Leijun; Huang, Hongjun; Zhang, Saijun; Zheng, Wentao; Yuan, Xiaoguang
• Is Part Of: Materials & design. Volume 212(2021)
• Publication Date: 2021-12-15
• Subjects: Cruciform biaxial tensile test -- Shear yield locus -- Anisotropic yield criterion -- Identification strategies -- Non-integer exponent -- Associated flow rule; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2021.110210
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: Cruciform biaxial tensile test were performed in rolling/transverse and 45°/135° sampling directions under different loading paths. Priority of calibrating the material parameters with the equi-biaxial data should be ensured. The introduction of plane strain yield stresses are positive for the accurate prediction of plastic anisotropy. Non-integer exponent is helpful to improve the description accuracy of anisotropy yield behavior. Biaxial tensile data under principal stress state are not enough to evaluate the best identification method. Abstract: It is necessary to identify differences among biaxial tensile mechanical properties to describe the plastic anisotropy and potential adjustment ability of yield criteria with the non-integer exponent for the yield surface. Therefore, in this study, uniaxial and cruciform biaxial tensile tests were performed under 17 different loading paths: uniaxial tension in seven different directions, cruciform biaxial tension in rolling/transverse and 45°/135° sampling directions with seven and three different stress ratios, respectively. Based on the BBC2008 yield criterion, the uniaxial yield stresses, r θ -values, yield loci on the normal plane, and shear yield loci on the diagonal plane, predicted using six parameter identification strategies, were quantitatively evaluated for MP980, DP490, 6016-T4, and 5182-O. Results show the constraining and regulation ability of the equi-biaxial tensile data for yield loci to be better than that of near-plane strain state data. The parameter identification strategy considering the non-integer exponent was observed to significantly improved the ability of the yield criterion to describe the anisotropic yield behavior. For a simplified evaluation system that considers only the prediction accuracy of the yield locus under the principal stress state, neglecting the prediction accuracy for the shear yield locus may lead to incorrect judgments regarding the best identification strategy.