抄録
Biaxial tensile tests of commercial pure titanium sheet, JIS #1, were performed using a servo-controlled multiaxial tube expansion testing machine developed by one of the authors [Kuwabara, T. and Sugawara, F., Multiaxial tube expansion test method for measurement of sheet metal deformation behavior under biaxial tension for a large strain range, Int. J. Plasticity, 45 (2013), 103-118.]. Tubular specimens with an inner diameter of 54 mm were fabricated from an as-received sheet sample with a thickness of 0.5 mm by roller bending and TIG welding. Many linear stress paths in the first quadrant of stress space were applied to the tubular specimens to measure the biaxial work hardening behavior of the test sample. Following conclusions were obtained: (1) the test material exhibited significant differential work hardening (DWH); (2) the work contour for ε^p_0= 0.05 was in fair agreement with that calculated using the Yld2000-2d yield function; (3) the work contour forε^p_0 =0.15 was in fair agreement with that calculated using Hill's quadratic yield function.
