抄録
This paper proposes a material modeling methodology of sheet metals using a numerical biaxial tensile test based on the crystal plasticity finite element (CPFE) method and the mathematical homogenization method. To demonstrate the feasibility of the proposed methodology, the biaxial tensile deformation behavior of 5182 aluminum alloy sheet was predicted by the numerical biaxial tensile tests of the sheet. The stress–strain curves and the shapes of the contours of plastic work calculated by the numerical biaxial tensile tests were quantitatively verified by the experimental biaxial tensile test using the cruciform specimen. Parameters of the Yld2000-2d yield function were identified using the results of experimental and numerical biaxial tensile tests. For comparison, von Mises's and Hill's yield functions were identified using the experimental data. To elucidate the effects of the yield functions on the accuracy of sheet metal forming simulation, finite element simulations of hydraulic bulge forming were performed using the identified yield functions. The simulation results demonstrated that the forming simulation using the Yld2000-2d yield function identified by the numerical biaxial tensile tests showed better accuracy than that of the Mises's and Hill's yield functions and was comparable to that of the Yld2000-2d yield function calibrated experimentally.
