Abstract:

In order to investigate the compression behavior of the cold-formed thin-walled steel columns with lipped channel,intermediate stiffener and openings in the web,16 axial compressive members,including the short and the medium-length columns in two section forms,were experimentally analyzed in the aspects of bearing capacity and buckling mode. The results show that all of the specimens fail due to the distortional buckling and the mediumlength columns have additional overall bending around the weak axis,that the openings in the web result in the changes of buckling modes of the members and the local bucklings of the plates occur around the openings,and that,due to the effects of the openings,the bearing capacities of the specimens decrease and the decrement of the bearing capacity of the short column is greater than that of the medium-length one. Moreover,it is found that,for the specimens in the same test group,the columns with larger initial distortional imperfections are of lower bearing capacities and greater deformations induced by the distortional bucklings,and that the openings generally enhance the deformations corresponding to the ultimate bearing capacity. In addition,all of the tested specimens are simulated by means of the finite element method,finding that the simulated results accord well with the experimental ones.

Key words: cold-formed thin-walled steel, lipped channel section, opening, experimental investigation, distortional buckling, finite element method