COLD-FORMED STAINLESS STEEL TUBULAR SECTIONS UNDER COMBINED COMPRESSION AND CYCLIC BENDING
F. Zhou 1*, C. Fang 1 and C. Luo 1
1 Department of Structural Engineering, Tongji University, Shanghai, China
The behaviour of stainless steel tubular sections under combined constant compression and uniaxial cyclic bending was reported in this study. The rectangular and square hollow section (RHS and SHS) specimens were tested, covering a variety of section slenderness, axial load ratio, and bending direction. These test parameters were found to have evident influences on the local buckling resistance of the specimens. It was also observed that the current codified classification limits underestimate the ability of the stainless steel sections to develop plastic stresses. Moreover, the specimens exhibited low to moderate levels of ductility due to a relatively early occurrence of local buckling. A numerical study was subsequently conducted, shedding further light on the strength, stress pattern, ductility, and local failure behaviour of the specimens. A more extensive parametric study was then carried out, which provides basis for the proposal of a ductility-oriented design approach that aims to offer a quick yet reliable evaluation tool for predicting the available ductility supply of stainless steel RHSs/SHSs under different loading conditions. The rationality of the current major design codes for predicting the strength of stainless steel members was also evaluated, and it was found that the design codes tend to be conservative.
Cyclic loading; Ductility; Local buckling; Hollow sections; Hysteretic response; Stainless steel.