Estimation Method for Flexural Strength for Distortional Buckling of Cold-formed Thin-walled Steel Lipped Channel Bending Member

distortional buckling bending capacity of 18 cold-formed thin-walled pure bending member in reference((1)) are analyzed and predicted by different methods in this paper, including 'Technical Code of Cold-formed Thin-Wall Steel Structures (GB50018-2002)', Direct Strength Method in ' North American Specification Supplement (NAS2004)', 'Cold-Formed Steel Structures Standard (AS/NZS4600:2005)'. The comparison show that, results estimated by 'Technical Code of Cold-formed Thin-Walled Steel Structures (GB50018-2002)' is more, flexural strengths predicted by NAS2004 and AS/NZS4600:2005 are lessreliability although theoreticalresults agree to result of test well, so a suggested method was been presentedto calculated the distortional buckling strength in this paper. Flexural strength estimated by the suggested methodhas good reliability and agree with result of test. So the suggested methodcan be effectively used to estimate flexural capacity of cold-formed thin-walled pure bending member with distortional buckling.