The Influence of Notch Depth on the Response of Local Sharp-Notched Circular Tubes under Cyclic Bending

In this paper, the mechanical behavior and buckling failure of SUS304 stainless steel tubes with different local sharp-notched depths subjected to cyclic bending were experimentally investigated. It can be seen that the experimental moment-curvature relationship exhibits cyclic hardening and becomes a steady loop after a few cycles. However, the experimental ovalization-curvature rela-tionship exhibits an increasing and ratcheting manner with the number of the bending cycles. In addition, higher notch depth of a tube leads to a more severe unsymmetrical trend of the ovaliza-tion-curvature relationship. It has been observed that the notch depth has almost no influence on the moment-curvature relationship. But, it has a strong influence on the ovalization-curvature re-lationship. Finally, the theoretical model proposed by Kyriakides and Shaw [1] was used in this study for simulating the controlled curvature-number of cycles to produce buckling relationship. Through comparison with the experimental data, the theoretical model can properly simulate the experimental finding