Feasibility of developing composite action between concrete and cold-formed steel beam

Cold-formed steel structures are steel structure products constructed from sheets or coils using cold rolling, press brake or bending brake method. These structures are extensively employed in building construction industry due to their light mass, ductility by economic cold forming operations, favorable strength-to-mass ratio and other factors. The utilization of cold formed steel sections with concrete as composite can hugely reduce the construction cost. However, the use of cold formed steel members in composite concrete beams has been very limited. A comprehensive review of developments in composite beam with cold formed steel sections was introduced. It was revealed that employing cold-formed steel channel section to replace reinforcement bars in conventional reinforced concrete beam results in a significant cost reduction without reducing strength capacity. The use of composite beam consisting of cold-formed steel open or close box and filled concrete could also reduce construction cost. Lighter composite girder for bridges with cold-formed steel of U section was introduced. Moreover, types of shear connectors to provide composite action between cold-formed steel beam and concrete slab were presented. However, further studies to investigate the effects of metal decking on the behavior of composite beam with cold-formed steel section and introduction of ductile shear connectors were recommended.

冷弯薄壁型钢龙骨式剪力墙抗震性能简化及精细化数值模拟研究

龙骨式剪力墙作为冷弯薄壁型钢龙骨体系结构的主要抗侧力单元,其抗侧性能是由覆面板、龙骨骨架及其间的自攻螺钉连接的性能决定。建立了基于自攻螺钉连接性能的精细化的冷弯薄壁型钢龙骨式剪力墙的有限元数值模型,并将龙骨与覆面板自攻螺钉连接的恢复力模型引入到剪力墙数值模型中,进行了墙体抗震滞回性能的数值模拟分析。结果表明,计算所得龙骨式剪力墙的弹性刚度、承载力以及变形等特征参数与试验结果吻合较好,该模型能够较为准确地反映龙骨式剪力墙的抗震滞回性能。在此基础上,提出了龙骨式剪力墙数值模拟的简化方法,为房屋整体结构抗震性能的数值分析提供了支撑。