摘要
为了准确评估黏滞阻尼器对斜拉索参数振动的控制效果。考虑斜拉索几何非线性、倾角以及塔梁协同振动的影响,引入阻尼器的附加刚度,建立黏滞阻尼器-斜拉索-塔梁组合体系的参数振动耦合模型,推导黏滞阻尼器作用下斜拉索的运动方程组,给出考虑附加刚度影响的黏滞阻尼器阻尼系数计算公式;编制程序分析阻尼器附加刚度对斜拉索固有频率和振动时程的影响水平,并与传统单索模型对比;研究三种典型索梁频率比下阻尼器附加刚度和安装位置对拉索参数振动的影响规律。结果表明:黏滞阻尼器的附加刚度对斜拉索的固有频率影响较大,但其安装位置对固有频率的影响较小;附加刚度越大,安装位置越远离索梁锚固端,两者的影响水平越高;阻尼器附加刚度对拉索的振动时程影响较大,会加速斜拉索的位移衰减;随着附加刚度的增大,拉索最大振幅呈现减小趋势,但振幅衰减率呈现先增大后趋于稳定的趋势,黏滞阻尼器-索梁系统存在一个最优附加刚度k;随着安装位置比u的增大,斜拉索的振幅和振幅衰减率均呈现非线性递减趋势,系统存在一个阻尼器临界安装位置比u,建议阻尼器的安装位置比控制在0.045以下。
In order to accurately evaluate the control effect of viscous dampers on the parametric vibration of stay cables,the effects of the geometric nonlinearity,inclination and tower-beam synergistic vibration of stay cables were considered and a coupled model for the parametric vibration of the viscous damper-stay cable-tower-beam system was established by introducing an additional stiffness,and the equations of motion of stay cables with viscous dampers were derived.A formula for calculating the damping coefficient of viscous dampers considering the effect of additional stiffness was proposed and the result was compared with that by the traditional single-cable model.The influence of the additional stiffness on the natural frequency and vibration time history of stay cables was analyzed numerically.The influences of the additional stiffness and installation position of viscous dampers on the parametric vibration of stay cables with three typical cable-beam frequency ratios were studied.The results show that the additional stiffness of viscous dampers has great influence on the natural frequency of the cable,but the installation position has little influence on the natural frequency;the greater the additional stiffness,the farther the installation position apart from the anchorage end of cable-girder,the higher the influences;the stiffness of dampers has great influence on the vibration time history of cables,which will accelerate the displacement attenuation of cable;with the increase of additional stiffness,the maximum vibration amplitude tends to decrease,but the amplitude attenuation rate increases first and then tends to be stable.There is an optimal additional stiffness k for the viscous damper-cable-beam system.With the increase of installation position ratio u,the amplitude and amplitude attenuation rate of stay cables show a non-linearly decreasing trend.There exists a critical installation position ratio u.It is suggested that the installation position ratio of dampers should be controlled to below 0.045.
作者
汪峰
李春清
刘章军
金旭光
WANG Feng;LI Chunqing;LIU Zhangjun;JIN Xuguang(Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang 443002,China;School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430074,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第22期183-191,共9页
Journal of Vibration and Shock
基金
国家自然科学基金项目(51778343)
2017年度防灾减灾湖北省重点实验室(三峡大学)开放基金(2017KJZ07)。
关键词
斜拉索
黏滞阻尼器
耦合模型
附加刚度
参数振动控制
long span cable
viscous damper
coupled model
additional stiffness
parametric vibration control
