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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 relationship 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 ovalization-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 relationship. 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 findings

The magnetization of Co0.10Ni0.90/Cu(001) films before and after surface oxidization at 300 K is presented. Before the oxidization, the magnetization of the films in the thickness of 11 to 20 monolayers (ML) is in the in-plane direction at the temperature ranging from 140 K to 300 K. After the oxidization, the magnetizations of the films are in the in-plane direction at the temperature above 200 K, but transit to magnetization demolishment, in-plane-and-out-of-plane co-existence, spin reorientation transition, and coercivity enhancement, for films of 11, 12, 13, and above 15 ML, respectively. The blocking temperature of this film is also 200 K, which implies the transitions might be driven by the ordering of the antiferromagnetic surface oxides. The various magnetizations provide a model system for manipulating the magnetization direction, as well as a spin valve device by combination of the oxidized films.

This paper presents the experimental result on the response and collapse of sharp-notched circular tubes subjected to cyclic bending with different curvature-rates. The tube bending machine and curvature-ovalization measurement apparatus were used for conducting the cyclic curvature-controlled experiments on sharp-notched 304 stainless steel tubes. According to the capacity of the bending machine, three different curvature-rates, 0.0035, 0.035 and 0.35 m -1 s -1 , were controlled to highlight the characteristic of the response and collapse. It is observed that the higher the applied curvature-rate, the greater is the degree of hardening on metal tube. However, the ovlization of tube cross-section increases when the applied curvature-rate increases. In addition, due to the higher degree of the ovalization of tube cross-section under cyclic bending, the number of cycles to produce collapse is corresponding reduces.