EXPERIMENTAL STUDY ON THE INTERACTIVE BUCKLING OF WELDED SECTION STEEL COLUMNS UNDER AXIAL COMPRESSION

摘要

The current Chinese code for design of steel structures GB 50017-2003 provides design method for the overall buckling of steel columns and sets limit values for the width-to-thickness ratios of plates to prevent the occurrence of local buckling.However,the design method for the columns with slender component plates,the width-to-thickness ratios of which exceed the limit values,is still not complete.In order to investigate the interactive behavior between overall and local buckling for welded section columns under axial compression,an experimental program consisting of 16 I section members and 12 box section members was carried out.The specimens were fabricated from 235MPa and 345MPa steel plates with a nominal thickness of 6mm.With slenderness ranging from 40 to 90 and width-to-thickness ratios of component plates larger than limit values,all the specimens were designed to interactively buckle.The overall and local geometric initial imperfections of all the specimens were measured before the axial compression tests as well as the stress-strain curves of the steel plates.The displacements and strain distributions of critical sections were recorded during the tests.Based on the test results,the interactive buckling of steel columns under axial compression was studied.And the test results were compared with the corresponding design methods in American and European design codes for steel structures(ANSI/AISC 360-10 and Eurocode 3)to confirm whether current design methods could be used.