論文
穴広げ成形シミュレーションの解析精度に及ぼす
異方性降伏関数の影響
異方性降伏関数の影響
2009 年 50 巻 585 号 p. 925-930
詳細
2009 年 50 巻 585 号 p. 925-930
We investigate the deformation behavior of a high-strength steel alloy in bore expansion both experimentally and analytically to clarify the effects of the material model (anisotropic yield function) on the predictive accuracy of finite element simulations of bore expansion. The test material used in the bore expansion test is a dual-phase steel alloy with a tensile strength of 780MPa. The elastic-plastic deformation behavior of the test material is precisely measured by biaxial tensile tests using cruciform specimens to determine the appropriate anisotropic yield function for the test material. The measured contours of plastic work and the directions of plastic strain rates are in good agreement with those predicted using Yld2000-2d with an exponent of 4. Moreover, forming simulations of and experiments on the bore expansion of the test material have been carried out. The anisotropic yield functions used in the simulation are von Mises, Hill’s quadratic and Yld2000-2d nonquadratic yield functions. Yld2000-2d with an exponent of 4 has given the closest agreement with the experimental results. Consequently, anisotropic yield functions significantly affect the predictive accuracy of the deformation behavior of a sheet in bore expansion.
