负刚度非线性黏滞阻尼器对斜拉索振动控制研究

Nonlinear viscous dampers paralleled with negative stiffness for cable vibration control

为提升传统被动线性黏滞阻尼器(LVD)对斜拉索的减振效果,本文融合被动负刚度控制技术和非线性黏滞阻尼特征,开展了负刚度非线性黏滞阻尼器(NSNVD)对斜拉索减振增效的研究。基于能量等效线性化方法获得了NSNVD的线性等效力学模型;采用复模态分析获得了斜拉索张紧弦模型的附加模态阻尼比的近似解和迭代解,并分别与考虑或忽略斜拉索垂度和抗弯刚度的数值仿真解进行对比,验证了能量等效线性化方法对NSNVD斜拉索减振系统的适用性;基于考虑斜拉索垂度和抗弯刚度的仿真解分别开展了NSNVD对斜拉索单模态减振效果参数分析和多模态减振效果优化研究,获得了NSNVD负刚度系数和黏滞阻尼指数对斜拉索单模态和多模态减振效果的影响规律。研究结果表明:NSNVD的被动负刚度效应显著提升了斜拉索单模态减振效果,负刚度效应和非线性黏滞阻尼特征均有助于提升斜拉索多模态减振效果;与非线性黏滞阻尼器(NVD)和负刚度线性黏滞阻尼器(NSLVD)相比,NSNVD对斜拉索具有更好的减振效果。

To enhance the cable vibration control performance of traditional passive linear viscous dampers(LVD),this paper investigates the cable vibration control performance of a negative stiffness parallel nonlinear viscous damper(NSNVD),which combines passive negative stiffness technique and nonlinear viscous damping characteristics.The linear equivalent model of the NSNVD is firstly obtained through the energy equivalent linearization method.Next,based on the complex modal analysis,the asymptotic and iterative solutions of the supplemental modal damping ratio of a taut cable are obtained,and compared with the numerical simulation solutions considering or neglecting the cable sag and bending stiffness.Accordingly,the applicability of the energy equivalent linearization method for the cable-NSNVD system is verified.Finally,based on the numerical simulation solutions considering the cable sag and bending stiffness,the parameter analysis of the single-mode vibration mitigation effect of the NSNVD and the optimization of the multi-mode vibration mitigation effect of the NSNVD on stay cables are carried out,which help to analyze the effects of the negative stiffness coefficient and viscous damping exponent of the NSNVD on single-mode and multi-mode vibration control performance of the cable.The results show that the passive negative stiffness of the NSNVD can significantly improve the single-mode vibration mitigation effect of stay cables.Moreover,both the negative stiffness and nonlinear viscous damping characteristics of the NSNVD are helpful to improve the multi-mode vibration mitigation effect of stay cables.Compared with the NVD and the NSLVD,the NSNVD presents more advantages in cable vibration control.