Cold-formed steel (CFS) unlipped channel sections are commonly used as bearers in floor systems while rectangular hollow sections (RHS) are used as joists. The transverse loads from the joists do not pass through the shear centre of channel bearers due to different joist to bearer and bearer to column connections. Hence, the channel bearers are subjected to torsion in addition to concentrated loads and bending. This study investigated the effects of two joist to bearer (bolted/welded) connections, two bearer to column (cap plate/angle cleat) connections and fly braces on the structural behaviour of channel bearers. Eight full-scale tests were performed using simplified floor arrangements, made of two unlipped channel bearers with eight and six RHS joists located at 450 mm spacing. Suitable finite element models of tested channel bearers including their connections were developed and validated in terms of ultimate failure moment, failure mode and deflections. A parametric study was then performed using the validated finite element models. The effects of bolted/welded joist to bearer connections and cap plate/angle cleat bearer to column connections on the behaviour of channel bearers were determined and discussed based on the experimental and numerical results. Suitable recommendations were then made to the design methods based on the observed failure modes, and the most suitable combination of connections for the CFS floor systems investigated in this study.

冷弯型钢（CFS）的无唇槽型材通常用作地板系统中的支撑物，而矩形中空型材（RHS）用作托梁。由于不同的托梁与承载件以及承载件与立柱的连接方式不同，来自托梁的横向载荷不会通过通道承载件的剪切中心。因此，除了集中的载荷和弯曲之外，通道承载件还受到扭转。这项研究调查了两个托梁到支座（螺栓/焊接）连接，两个支座到立柱（盖板/角夹板）连接以及花撑对通道支座结构行为的影响。使用简化的地板布置进行了八次全面测试，该地板布置由两个未唇槽的通道支撑物组成，其中八个和六个RHS托梁的间距为450 mm。根据极限破坏力矩，破坏模式和挠度，开发并验证了经过测试的通道承载的合适的有限元模型，包括它们的连接。然后使用经过验证的有限元模型进行参数研究。基于实验和数值结果，确定并讨论了螺栓/焊接托梁到支座的连接以及盖板/角夹板支座到立柱的连接对通道支座性能的影响。然后，基于观察到的故障模式以及本研究中研究的CFS地板系统的最合适的连接组合，对设计方法提出了适当的建议。然后使用经过验证的有限元模型进行参数研究。基于实验和数值结果，确定并讨论了螺栓/焊接托梁到支座的连接以及盖板/角夹板支座到立柱的连接对通道支座性能的影响。然后，基于观察到的故障模式以及本研究中研究的CFS地板系统的最合适的连接组合，对设计方法提出了适当的建议。然后使用经过验证的有限元模型进行参数研究。基于实验和数值结果，确定并讨论了螺栓/焊接托梁到支座的连接以及盖板/角夹板支座到立柱的连接对通道支座性能的影响。然后，基于观察到的故障模式以及本研究中研究的CFS地板系统的最合适的连接组合，对设计方法提出了适当的建议。