Behaviour of hollow curved steel struts subjected to compressive load

Abstract

Experimental tests have been performed on hollow curved steel struts in order to investigate the stability and general behaviour of such struts. Two different manufactured types of tubes were used: electric resistance welded tube (ERW) with 60.4 mm outside diameter and 2.3 mm wall thickness, and hot finish seamless tube (HFS) with 60.4 mm outside diameter and 4 mm wall thickness. The strut tests were effectively pin-ended and had slenderness ratios, based on the straight length between ends, ranging from 37 to 147. Although the experimental results showed that the ultimate load capacity of curved steel struts decreased with decreasing initial radius of curvature due to increasing initial deflection at mid-height, as expected, the post-buckling behaviour of the seamless struts was significantly different from that of the ERW struts. It is seen that the ultimate load capacity of stress-relief-annealed (SRA) curved struts is significantly reduced in comparison with the equivalent as-received (AR) struts. Also, it is observed that the Bauschinger effect is not significant for the curved struts tested herein, although it has been seen to be significant for straight struts.