Resumen
In this study, the response of local sharp-notched SUS304 stainless steel tubes with different notch depths of 0.2, 0.4, 0.6, 0.8 and 1.0 mm subjected to cyclic bending at different curvature-rates of 0.0035, 0.035 and 0.35 m-1s-1 were experimentally investigated. The tube bending machine and curvature-ovalization measurement apparatus, which was designed by Pan et al. [1], were used for conducting the curvature-controlled cyclic bending. For a constant curvature-rate, the moment-curvature curve revealed that the cyclic hardening and became a steady loop after a few bending cycles; the notch depth had almost no influence on the curves. Moreover, the ovalization-curvature curve increased in an increasing and ratcheting manner with the number of bending cycles. Large notch depths resulted in larger ovalization of the tube cross-section. In addition, for a constant notch depth, higher curvature-rates led to larger cyclic hardening and faster increasing of ovalization.