Flexural buckling of elliptical hollow section columns

Complementary to recent studies on the cross-section behavior of elliptical hollow sections, investigations into the member response have also been performed and described in this paper. The first stage of these investigations involved a series of precise column buckling tests on hot-finished steel elliptical hollow sections. In total, 24 flexural buckling tests about the minor and major axes were carried out. Specimen sizes and lengths were carefully chosen in order to cover a wide range of both cross section and member slendernesses. The nondimensional column slenderness of the test specimens varied between 0.19 and 1.58. Measurements were taken of specimen geometry, global initial geometric imperfections, and tensile material properties. Key results from the tests including the full load-deformation histories have been presented and discussed. The test results have also been supplemented by 158 numerically generated results, allowing a wider range of geometries to be investigated. Design rules for the member buckling resistance of elliptical hollow section columns have been proposed and verified by means of reliability analysis. The results presented are the first member buckling tests on elliptical hollow sections, and represent part of the development of comprehensive structural design rules for these sections.