剪力墙竖向连接软钢阻尼器滞回性能试验研究

Experimentalrimental research on hysteric performance of mild steel damper for shear wall vertical connection

提出应用于剪力墙竖向韧性连接体的易拆装的拉压耗能软钢阻尼器.为了研究拉压荷载作用下该阻尼器的滞回性能,基于杠杆原理,设计制作能放大加载位移的高承载销轴-钢梁加载装置和3对不同耗能肢形状的试件,模拟阻尼器的螺栓连接边界和拉压往复受力过程.将阻尼器试件同条件依次安装并开展拟静力循环往复加载试验,研究试件的破坏模式、强度及变形能力、耗能特性及螺栓连接的可靠性,获得试件的滞回曲线、骨架曲线、刚度退化曲线、承载力及延性系数等.对阻尼器的耗能承载能力进行评价分析,研究耗能肢型体参数对力学性能的影响.建立有限元模型,模拟阻尼器的失效行为.结果表明,阻尼器以耗能肢屈曲为典型破坏模式,Z型耗能肢阻尼器与其他2种耗能肢形状的阻尼器相比,具备更好的防屈曲性能和耗能能力,能够发挥低屈服点钢材的力学性能,震损后可以快速更换.

A tension-compression type demountable mild steel damper for shear wall vertical connections was proposed and could highly increase this structure’s energy dissipation ability. A loading structure with high strength and three pairs of damper specimens with different limb geometrical shapes were designed based on the lever principle in order to analyze the hysteric behavior of this tension-compression damper. The structure can enlarge the displacement load. The bolt connection boundary condition and the tension-compression cyclic loading process were simulated. These specimens were respectively installed on the loading structure and tested in the same condition to analyze their failure modes, strength, ductility, energy dissipation ability and the reliability of the bolt connection.Their cyclic load-displace curves, skeleton curves, stiffness degradation curves, strength and ductility coefficients were utilized to evaluate their bearing and energy dissipating abilities. The influence of the limb geometrical shape on their mechanical behavior was analyzed. The finite element model was constructed to simulate the dampers ’failure behavior. The buckling of damper limbs was analyzed as the typical failure mode. The Z-type mild steel damper exhibits higher buckling-restrained and energy dissipating ability than that of the other two types, make full use of the material performance of low yield point steel, and could be rapidly replaced after being damaged.