关键词: 商用汽车板材, 塑性各向异性, 参数识别策略, 近平面应变载荷, 关联流动法则

Abstract:  With the increasing demands for forming accuracy of stamped parts in the modern automobile industries， the accuracy of models describing the deformation behavior of commercial sheet metals should be improved accordingly. In the context， a parameter identification strategy was proposed based upon uniaxial tension， equi-biaxial tension， and near-plane strain data to calibrate advanced anisotropic yield criteria， combined with current industrial laboratory testing capabilities. The newly proposed calibration method was applied to the BBC2008 yield criterion and compared with several other yield criteria， including the widely used Hill48 and Balat89 in the industry， as well as Yld2004-18p， Yld2011-27p， Yoshida2013， and Poly4*Hosford， which had similar flexibility to BBC2008. The effectiveness and applicability of the new parameter identification strategy were verified by quantitatively evaluating the predicted errors of the yield loci in the normal and diagonal planes， equi-biaxial and uniaxial tensile yield stresses， and plastic strain rations for MP980 and SPCE steels， as well as 5182-O and A6XXX-T4 aluminum alloys. The results show that the new method may comprehensively improve the ability to describe plastic anisotropy， especially for diagonal plane shear yield loci. There are significant differences in the ability of different yield criteria to describe the anisotropic behavior of commercial sheet metals. In particular， under the premise of calibrating yield criteria with the same mechanics properties data， releasing the potential adjustment ability of the exponent is more important than increasing the number of material parameters. 

Key words: commercial automobile sheet metal, plastic anisotropy, parameter identification strategy, near plane strain loading, associated flow rule