Interaction buckling phenomena in thin-walled structures
- Kim Rasmussen
- Ben Young
Considerable effort has been devoted to characterising the overall buckling behaviour of locally buckled structural members. Using a rigorous bifurcation theory the effect of local buckling is accounted for by calculating the instantaneous stiffness at increasing levels of loading. The stiffness terms include axial, flexural and warping terms and lead to a wider range of coupling phenomena than in the case of non-locally buckled sections. Among other results, it is shown that local buckling can change the critical overall buckling mode of a channel section from a flexural-torsional to a flexural mode. Similarly, local buckling causes the overall buckling mode of a Z-section to change from a minor axis flexural buckling mode to a bi-axial buckling mode.
The research has focussed on columns, beams and beam-columns. The buckling behaviours of point symmetric sections, such as Z-sections, singly symmetric sections, such as channel sections, and doubly symmetric sections, such as I-sections, have been categorised. Column tests have been performed on Z-sections and channels sections to validate the theory.
The project is supported by the University of Sydney Research & Development scheme.