Study on a Stiffened Circular Steel Hollow Section Under Axial Compression

The most common method to enhance the load-carrying capacity of steel tubular sections is to integrate them with other steel elements using different techniques such as welding and bolting. Due to its low cost and tendency to delay buckling, stiffening is a frequently used technique for strengthening steel columns. The majority of the strengthening works are carried out by carbon fibre-reinforced polymer (CFRP) wrapping or with concrete-filled steel tubular columns. In the present work, experimental and analytical studies were carried out on nine hot-rolled circular hollow sections (CHS), out of which three specimens were unstiffened, three specimens were transversely stiffened and the remaining three were longitudinally stiffened. The load–deflection behaviour, load enhancement of stiffened specimens and failure modes are also discussed in this paper. The study revealed that the load-bearing capacity of the CHS column was enhanced by 3.54% with transverse stiffening and 57.42% with longitudinal stiffening, clearly indicating that longitudinal stiffener is more efficient than transverse stiffener.