壁挂式冷弯型钢结构双层组合墙体抗震性能试验研究

Experimental study on seismic performance of two-story walls in ledger-framed cold-formed steel buildings

为研究壁挂式连接冷弯型钢结构中双层组合墙体的抗震性能,对4个足尺双层墙体试件进行了水平低周往复试验,考虑了刚性斜撑、方钢管端柱加强、下部两层墙体抗侧刚度比等因素对墙体抗震性能的影响。结果表明:增设刚性斜撑墙体中V形刚性斜撑与墙面板蒙皮作用同时发挥抗侧作用,提高了墙体的受剪承载力及弹性抗侧刚度,但延性降低;采用方钢管截面端柱可避免端柱发生压屈破坏,其对墙体的抗侧刚度及受剪承载力提高幅度较小,但可以改善墙体的延性及变形性能;当底层与二层墙体抗侧刚度比大于1时,墙体属于弯曲型破坏。建议在多层冷弯薄壁型钢结构住宅抗震设计中,对底层墙体设置刚性斜撑、采用方钢管加强端柱以提高墙体受剪承载力及端柱抗压屈能力。

In order to study the seismic performance of two-story walls in ledger-framed cold-formed steel buildings,a total of four full-scale specimens were tested under two-point horizontal reversed cyclic loading.The effects of rigid diagonal bracing,square steel column,and lateral stiffness ratio of lower two-story walls were analyzed.The results show that the V-shaped rigid diagonal bracing and wall sheathing work together to provide lateral resistance,leading to greatly improved shear capacity and elastic lateral stiffness,but the ductility is reduced.The use of square steel section can avoid the compressive buckling of the end column and improve the ductility and deformation performance of the wall,although it has little effect on the lateral stiffness and shear capacity of the specimen.The failure of the specimen with the stiffness ratio of bottom and upper walls of more than 1 can be categorized as bending failure.Finally,in the seismic design of multi-story cold-formed thin-walled steel structure residence,it is suggested to adopt rigid diagonal braces,and use square steel tubes as end columns to improve the shear bearing capacity and compressive buckling resistance of the bottom wall.