ANALYSIS OF EFFECTIVE SECTION OF COLD-FORMED THIN-WALL LIPPED CHANNEL PURLINS

Based on the contrast analysis of Eurocode 3 ( EN1993 －1－3) and Technical Code of Cold-Formed Thin-Wall Section Steel Structure( GB 500182002)，analysis and discussion are mentioned about the effective section of cold-formed thin-wall lipped channel purlins． The results showed that the provisions of the effective section modulus in the GB 50018 2002 specifications were too conservative，while the results were close to each other by the Eurocode 3 and facts． Under full stress condition， the reduction factor of the effective section modulus of cold-formed thin-wall lipped channel purlins from C180 to C250 ( 2 mm thickness) was 0. 9 ( Q235 steel) and 0. 8 ( Q345 steel) respectively．