大悬挑结构抗风拉索弹簧-阻尼减振支座性能试验与风振控制研究

Performance tests and wind-induced vibration control of anti-wind cable spring-damping vibration reduction bearing for large cantilevered structure

为提高大悬挑结构的抗风性能,提出将圆柱螺旋弹簧与筒式黏滞阻尼器相结合设计形成弹簧-阻尼减振支座,并将其布置在柱顶与拉索配合起到竖向减振的作用。对该弹簧-阻尼减振支座的力学性能进行试验研究,依次开展了轴向刚度与低周往复加载试验共计61种工况,探究了静位移、位移幅值与加载频率对支座力学性能的影响,并基于有限元软件对安装弹簧-阻尼减振支座前后的体育场结构进行风振动力响应分析。结果表明:支座的轴向刚度随加载等级的增加而增大;支座的滞回耗能性能随位移幅值的增加而增大,等效阻尼比和等效刚度则随位移幅值的增大而减小;与支座性能随位移幅值的变化情况相比,其力学性能随加载频率的变化幅度更小,各个区段变化范围均小于±10%;静位移对支座的滞回耗能性能、等效刚度和等效阻尼比影响较小。弹簧-阻尼减振支座对大悬挑结构的风振响应具有显著的控制效果,最大达92.16%,平均38.79%。

Here, to improve anti-wind performance of long-span cantilevered structure, a spring-damping vibration reduction bearing designed by combining cylindrical coil spring with cylindrical viscous damper was proposed, and it was arranged on top of the structure column to cooperate with cable, and play the role of vertical vibration reduction. Mechanical properties of the spring-damping vibration reduction bearing were tested and studied. Axial stiffness and low cycle reciprocating loading tests were conducted under 61 working conditions, respectively and effects of static displacement, displacement amplitude and loading frequency on mechanical properties of the bearing were explored. Wind-induced dynamic response analyses of a stadium structure before and after installation of the bearing were performed based on finite element software. The results showed that the axial stiffness of the bearing increases with increase in loading level;the hysteretic energy dissipation performance of the bearing increases with increase in displacement amplitude, while its equivalent damping ratio and equivalent stiffness decrease with increase in displacement amplitude;compared to bearing performance changes with displacement amplitude, its performance changes with loading frequency are smaller, and variation range of each sector is less than ±10%;static displacement has smaller influence on its hysteretic energy dissipation performance, equivalent stiffness and equivalent damping ratio;the bearing has a significant control effect on wind-induced vibration responses of long-span cantilevered structure, the maximum vibration reduction effect is 92.16%, and the average value is 38.79%.