黏滞阻尼器联合负刚度对斜拉索减振控制的增效研究

Performance enhancement of the viscous damper combined with the negative stiffness device for cable vibration control

阻尼器的负刚度特性有助于提升其对斜拉索的减振效果,为探究负刚度装置(NS)对黏滞阻尼器(VD)应用于斜拉索减振控制的增效作用,开展了VD联合NS对斜拉索减振控制的增效研究。采用复模态分析方法获得了斜拉索-VD-NS耦合系统的特征方程,并进一步推导了斜拉索附加模态阻尼比的近似解;分析了NS的负刚度系数和安装高度对斜拉索模态阻尼比和振动频率的影响;基于输出反馈的LQR控制,获得了给定负刚度系数时VD对斜拉索多阶模态减振控制的最优参数,进而研究了负刚度系数和NS安装高度对斜拉索多阶模态振动控制的增效作用。研究结果表明:增加NS的负刚度系数或安装高度均有助于提升VD对斜拉索单阶模态和多阶模态减振效果,同时减小了VD的最优阻尼系数;NS对VD减振性能的提升归功于负刚度系数或NS安装高度的增大对VD位移幅值的放大效应,提升了VD的耗能能力。

The negative stiffness behavior of a damper can improve its performance for cable vibration control.To explore the performance enhancement effect of the negative stiffness(NS)device on the viscous damper(VD)in mitigating cable vibrations,the combined effect of the VD and NS for cable vibration control is investigated.The characteristic equation of the cable-VD-NS system is established based on the complex modal method.On the basis,the asymptotic solution of the cable modal damping ratio is derived.The effect of the NS coefficient and the NS location on the modal damping ratio and vibration frequency of the cable is evaluated.Based on the constrained static output LQR method,the design parameters of the VD for a given NS coefficient for suppression cable multi-mode vibrations are obtained.Furthermore,the effect of the NS coefficient and the NS location on the VD performance in mitigating cable multi-mode vibrations is investigated.The results show that increasing the NS coefficient or the NS location can improve the control performance of the VD and reduce the optimal damping coefficient of the VD,including the singlemode and multi-mode vibrations of the cable.The performance enhancement of the NS on the VD is mainly attributed to the increment of the NS coefficient or the NS location can amplify the displacement of the VD,which can improve the energy dissipation capacity of the VD.