高强超薄壁冷弯型钢屋架承载性能及设计方法研究

Load-carrying behavior and design method of high-strength thin-walled cold-formed steel roof trusses

摘要:

基于三榀厚度小于2mm、屈服强度550MPa的高强超薄壁冷弯型钢屋架模型结构的承载力试验，观测了这类低层住宅建筑常用屋架结构的破坏模式，得到了其极限承载能力。同时，采用通用有限元软件建立了该屋架结构考虑材料和几何非线性分析模型，进行了屋架结构非线性稳定分析，得到了与承载力试验结果相一致的破坏模式。在此基础上，研究了屋架结构内力分析的合理计算模式，并结合国、内外冷弯薄壁型钢设计规范的规定，提出了屋架构件的建议设计方法，并对屋架的屋脊节点板构造提出了合理的局部加强改进方案。

Abstract:

In this paper, experiments on three roof truss models made of thin-walled cold-formed steel channel sections with thickness less than 2mm and yield strength over 550Mpa were carried out, and the failure modes and load-carrying capacities of the roof truss structures were investigated. Furthermore, FEM analysis model considering geometry and material non-linearity was established, and non-linear stability analysis was performed on the tested model. It was shown that both failure modes and ultimate load-bearing capacity were consistent with test results. Based on the experiments and numerical analysis, reasonable calculation model for such roof trusses was studied, and the design method for structural members of the trusses were presented according to related national and foreign cold-formed steel structure design codes. Moreover, an improved construction details for strengthening rigidity of the ridge joint plate was also proposed.