抄録
The consideration of plastic anisotropy is useful in carrying out more precise simulation of bulk forming as well as of sheet forming. We have tried a small-cube compression test to determine the anisotropic coefficients F, G, H, L, M, and N of Hill's quadratic criterion (1948). A cubic specimen was cut out of a bar, which had 1-mm-long edges and whose normal axis at the center of each surface is closely related to the original r-, θ-, or z-axis in cylindrical coordinates. The small cube was compressed in the specific direction under a well-lubricated condition, before the strain ratios of edges were measured to determine the anisotropic coefficients. For examples, an extruded bar of A6063 and a rolled bar of SUS430 in JIS indicated F/G/H/L/M/N values of 1.0/1.0/0.40/1.2/1.1/1.9 and 1.1/0.89/1.1/2.2/2.4/2.4, respectively. The results of the small-cube compression test were verified by FE analysis considering anisotropy. Furthermore, we applied the small-cube compression test to estimate the distribution of the anisotropic properties of the bar in the radial direction.
