EXPERIMENTAL INVESTIGATION AND DESIGN OF CONCRETE-FILLED COLD-FORMED THIN-WALLED STEEL TUBES SUBJECT TO BENDING

摘要

A series of bending tests of thin-walled concrete-filled cold-formed steel tubes(CFST) were presented in this study.A total of 4 specimens were tested,two square specimens and two rectangular specimens,with width to wall thickness ratio ranging from 50 to 100.The failure mode and ultimate capacity of test specimens were obtained.A novel nonlinear analytical model was developed for the hin-walled CFSTs under bending.Nonlinear constitutive models of the confined concrete and steel tube,corner strength enhancement of the steel cross-sections,welding residual stress and local buckling were considered in the developed model.The predicted capacity calculated using the model proposed and it si shown that the model predictions agreed with the test result well.In addition,predictions from current AISC standard,Eurocode 4 and model proposed by other researcher were also compared with the test results.