Material properties of cold-formed and hot-finished elliptical hollow sections

This paper presents the material properties of both cold-formed and hotfinished elliptical hollow sections. The material properties of the elliptical hollow sections caused by different formation processes are investigated. Tensile coupon specimens extracted from different locations across the cross-sections were tested. The mechanical properties of the cold-formed and hot-finished elliptical hollow sections, such as the initial Young's modulus, 0.2% proof stress (yield stress), ultimate tensile strength, strains at ultimate strength and fracture as well as Ramberg-Osgood parameter that describe the shape of stress-strain curve, were obtained. The mechanical properties of the cold-formed elliptical hollow section obtained from the coupon tests were compared with those of the hot-finished elliptical hollow section. In addition, residual strains in the cold-formed and hot-finished elliptical hollow sections were also measured. The strain measurements involved both the longitudinal and transverse directions across the cross-sections, and the residual strain distributions in the cold-formed and hot-finished elliptical hollow sections were plotted. In this study, the test data obtained from the tensile coupon tests and the residual strain measurements for both cold-formed and hot-finished elliptical hollow sections are valuable information for future analytical, numerical and theoretical studies on elliptical hollow sections.