Inelastic buckling of single-angle, tee and double-angle struts

The inelastic flexural and flexural-torsional buckling of axially-loaded, pinned end single angle, tee and double angle struts are investigated theoretically. The calculated inelastic buckling loads are based on the tangent modulus concept, assuming idealised residual stress distributions in the strut sections. In the inelastic range, although the elastic flexural-torsional buckling loads for some struts are less than the elastic flexural buckling loads, results show that the inelastic buckling loads of the struts are not at all influenced by nor related to the elastic flexural- torsional buckling loads. It is found flexural buckling mode is the dominant failure mode for most of the strut shapes, except for single unequal angles and for tees and double angles whose radii of gyration ratios, r (sub x)/r (sub y) are greater than 1.0. Experimental results compare well with the ultimate strength curves, except for tee struts in which experimental buckling loads are consistently lower than the theoretical predictions. (Author/TRRL)