高强冷弯薄壁型钢卷边槽形截面轴压柱畸变屈曲试验研究

Experimental study on distortional buckling of high strength cold-formed steel lipped channel columns under axial compression

本文对550MPa高强冷弯薄壁型钢卷边槽形截面轴压构件畸变屈曲性能进行了试验研究,17根试件的试验结果表明:由于试件局部屈曲一般发生在畸变屈曲之前,促使畸变屈曲提前出现,这种相关作用减弱了构件整体刚度,降低了构件承载力;澳洲规范AS/NZS 4600:1996及北美规范NAS 2004中关于发生畸变屈曲构件承载力的计算方法没有考虑局部屈曲和畸变屈曲相关作用的不利影响。依据试验结果本文提出了一种修正直接强度法的建议计算方法,该法计算结果与试验结果较为接近且偏安全。

The distortional buckling behavior of 550MPa high strength steel cold-formed lipped channel column under axial compression loading has been studied in this paper. The test results of 17 specimens show that the local buckling usually appears before distortional buckling of the specimens and it causes advance distortional buckling. This interaction of local and distortional buckling may reduce the stiffness and beating capacity of the columns. The design methods for distortional buckling in specification AS/NZS 4600：1996 and Direct Strength Design Method （DSM） in specification NAS 2004 haven＇t considered the adverse interaction between local and distortional buckling. Based on the test results, a suggested method revised from DSM, which could account for such an adverse interaction has been put forward. The results calculated by the proposed method are close and conservative to test results.