EXPERIMENTAL STUDY ON LOCAL BUCKLING OF HIGH STRENGTH STEEL SQUARE BOX SECTION STUB COLUMNS UNDER AXIAL COMPRESSION

Aiming at the local buckling behavior of high strength steel welded box section columns,four axial compression tests of Q460 square box section stub columns were conducted.Based on the test results,the relation of buckling stress and ultimate stress of specimens with different width-to-thickness ratios were studied.Besides,test results were compared with the corresponding design methods and calculation formulae in Chinese,American,European steel structures design codes and method proposed by Chen Shaofan.The research work showed that the effective areas decreased and the post-buckling strength increased with width-to-thickness ratios;the value of the buckling stress of square box section stub columns in the Chinese steel structures design code was unreasonable;the calculation results of the American,European steel structures design codes and the design method proposed by Chen Shaofan were close,which were all little higher than the test results,so all the design methods were reasonable.A new design method was proposed to predict buckling stress of Q460 square box section stub columns,which was in need of revision;the design method proposed by Chen Shaofan and the calculating formula of Eurocode 3,which was in need of revision,were recommended to predict ultimate stress of Q460 square box section stub columns.