冷弯薄壁型钢双肢拼合构件轴压承载力研究

目前我国相关规范对冷弯薄壁型钢组合截面构件的承载力设计方法比较粗略。基于已有的卷边槽形截面构件和由其组成的组合箱形截面构件的轴心受压承载力试验研究结果，通过有限元模拟和理论分析研究了此类构件拼合前后的受力性能的差异。分析了安装误差和连接件间距对拼合构件承载力的影响。提出了针对组合箱形和工字形截面构件的轴心受压承载力设计方法。研究表明，组合箱形截面构件的整体屈曲和畸变屈曲承载力较单肢截面构件有一定提高，而组合工字形截面构件仅整体屈曲承载力有一定提高。设计承载力与试验结果的比较表明，所提出的建议设计方法基本合理，可为相关规范的编制提供参考。

Investigation on ultimate-capacity of built-up columns with double channel sections under axial compression

Built-up section members have been widely used in cold-formed thin-walled steel structures, but nowadays design methods for load-carrying capacity provided in related specifications in China are rather rough. The existing axial compression tests on lipped channel section members and built-up box section members, which are composed of lipped channel section members by self-drilling screws, are briefly introduced. The structural behaviors differences of built-up members and individual members were studied through existing experimental data, numerical analysis and theoretical studies. Then, the effects of installation errors and fastener spacing on built-up members’ultimate capacity were studied. Finally, a design method for built-up members with box and I sections under axial compression was proposed based on the above analysis.It can be concluded from this research that built-up box section member’s global and distortional buckling strength and built-up I section member’s global buckling strength are higher than corresponding single section member’s strength, and the existing test results can verify the reasonability of the proposed design method.