角撑加强型冷弯薄壁型钢组合墙体受剪性能试验研究

Experimental study on shear behavior of cold-formed thin-walled steel composite walls with bracket

为研究角撑加强型冷弯薄壁型钢组合墙体的受剪性能,设计了1个无角撑的冷弯薄壁型钢骨架、1个角撑加强型冷弯薄壁型钢骨架和8个角撑加强型冷弯薄壁型钢为骨架,并以石膏板或OSB板作为覆面板的组合墙体试件进行了水平单调加载和有、无竖向荷载作用的水平低周反复加载试验,对比分析了钢骨架和组合墙体的刚度、受剪承载力、位移延性系数、能量耗散系数等力学性能指标。对钢骨架受剪承载力及延性、单面板与双面板墙体承载力、墙体竖向荷载以及角撑长度进行了有限元分析,结果表明:角撑加强能够有效提高组合墙体的抗震性能,使得骨架的受剪承载力和位移延性系数分别提高40%和17%左右;单调荷载作用下,OSB板和石膏板覆面的角撑加强型双面板墙体受剪承载力约等于相应单面板墙体2倍承载力与其骨架承载力之差;无竖向荷载低周反复加载下墙体的受剪承载力和刚度较单调加载下的低,但其延性较好;当竖向荷载在120 kN以内能够使低周反复作用下试件的刚度、受剪承载力、延性和耗能能力得到较大提升,但当竖向荷载超过120 kN时墙体的抗震性能降低。角撑投影长度与立柱长度比值约为1/12的组合墙体抗震性能最好,增大或减小角撑长度均会使墙体的抗震性能降低。

In order to study the shear behavior of cold-formed thin-walled steel composite walls with bracket,one cold-formed steel frame without bracket,one cold-formed steel frame with bracket and eight cold-formed steel composite walls with bracket sheathed with gypsum boards or OSB were tested under monotonic loading,cyclic loading with vertical loading or not.The lateral stiffness,shear capacity,ductility coefficient and energy dissipation coefficient of cold-formed steel frames and composite walls with bracket were analyzed.The shear capacity and ductility of steel frame,the shear capacity of single-sided and double-sided shear walls,the vertical loading and the length of bracket of the walls were analyzed by finite element analysis.It is found that using brackets can enhance the seismic performance of the shear wall effectively and the shear capacity and ductility coefficient of cold-formed steel framing can be increased by about 40%and 17%,respectively.Under monotonic loading,the shear capacity of cold-formed steel double-sided boards composite walls with bracket sheathed with gypsum boards and OSB is about twice that of the single-sided boards composite walls minus the shear capacity of cold-formed steel frames.The shear capacity and lateral stiffness of the shear wall under cyclic loading without vertical load are lower than those under monotonic loading,but its ductility is better.When the vertical load is within 120 kN,it improves the shear performance of cycle loading specimens.However,the vertical load exceeding 120 kN will reduce the seismic performance of the wall.The seismic performance of composite wall is the best when the ratio of projection length of bracket to column length is about 1/12,and increasing or decreasing the length of bracket will reduce the seismic performance of the wall.