The Influence of Curvature-Rate on the Response and Collapse of Sharp-Notched Circular Tubes under Cyclic Bending

Abstract

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.

The Influence of Diameter-to-Thickness Ratios on the Response and Collapse of Sharp-Notched Circular Tubes under Cyclic Bending

“…Lee [21] examined the mechanical behavior and buckling failure of sharpnotched circular tube under cyclic bending. Hung and Lee [22] investigated the influence of curvature-rate on the response and collapse of sharp-notched circular tubes under cyclic bending. However, those studies considered sharp-notched tubes with a constant D o / t ratio.…”