Experimental Study on Fire Resistance of Steel Tube Columns Protected by Cedar Wood under Axial Load

摘要

Cold-formed steel has higher strength weight ratio and material distribute optimum reasonable sectional form can be carried out according to the practical requirement. It will produce high economic benefits when it is used as mainly strength components of the multi-layer or lower buildings. Resent studies about the cold-formed beam-column joints are mainly carried out under single direction load, and there are few studies on seismic performance. So it is necessa ry to make the seismic study to these joints. In this paper, we design the moment connectionsi all structural mem bers such as beams and columns are formed with lipped C-section back-to-back; moment connections between beams and columns are formed with hot-rolled steel gusset strength bolts;only the webs of lipped C-sections are bolted on to gusset plates with high strength bolts. A simple method employing shell elements and spring elements was ex plored in finite element analyses to simulate the bolted connections. A lot of three-dimensional parameter finite ele ment models were set up, the performance of moment connection is determined by the section thickness and the bolt intervals. The best section thickness for this joint was put forward according to finite element analysis. The rules were proposed for engineers concerned to design this sort of connections.