高强超薄壁冷弯型钢屋架承载性能及设计方法

Load-carrying Behavior and Design Method of High-strength Cold-formed Thin-walled Steel Roof Trusses

基于三榀厚度小于2mm、屈服强度550 MPa的高强超薄壁冷弯型钢屋架模型结构的承载力试验,观测这类低层住宅建筑常用屋架结构的破坏模式,得到其极限承载能力.采用通用有限元软件,建立该屋架结构考虑材料和几何非线性的分析模型,进行屋架结构非线性稳定分析,得到与承载力试验结果相一致的破坏模式.在此基础上,研究屋架结构内力分析的合理计算模式,提出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.

Experiments were carried out on three roof truss models which were made of thin-walled cold-formed steel channel sections with thickness less than 2 mm and the yield strength over 550 MPa to investigate the failure modes and load-carrying capacities of the roof truss structures. Furthermore, a finite element method analysis model was established by taking the geometry and material non-linearity into consideration, and a non-linear stability analysis was made on the tested model. Both failure modes and ultimate load-bearing capacity were consistent with test results. Based on the experiments and numerical analysis, reasonable calculation model for estimating the load-carrying capacity of such roof trusses was studied, and the design method for structural members of the trusses was presented. Finally, an improved construction details for strengthening rigidity of the ridge joint plate was also proposed.