Experimental study and load-carrying capacity analysis of eccentrically-compressed high-strength cold-formed thin-walled steel lipped channel columns

In this paper,ultimate load-carrying capacities of 48 specimens of eccentrically-compressed cold-formed thin-walled lipped channel columns made of 550MPa yield strength steel with different sectional dimensions,wallthickness,slenderness ratios,and bending axis,have been tested in order to investigate the buckling modes,effects of different factors,and the suitable method for estimating the load-carrying capacity of these members.It is shown that,local buckling and distortional buckling have important effects on high-strength cold-formed thin-walled steel eccentrically-compressed columns due to its high-strength in material and large width to thickness ratio in section,the estimated loading capacities based on ‘Technical code of cold-formed thin-walled steel structures’(GB 50018— 2002) may be unsafe for members with distortional buckling failures,while conservative for members with large slenderness ratios but without distortional buckling failures,since the local buckling effect has been carefully considered in the code,but no enough consideration for distortional buckling effect.Finally,based on the experimental and the corresponding calculated results based on current related codes,a suggested method to estimate the load-carrying capacity for eccentrically-compressed high-strength cold-formed thin-walled steel lipped channel columns has been presented,and the results calculated by the proposed method are in good agreement with the test results,by which the suitability of the presented method is established.