柔性支撑下负刚度阻尼器的拉索减振效果研究

Research on Cable Vibration Control Using Negative Stiffness Dampers with Flexible Supports

斜拉桥是大跨度桥梁常用的形式。拉索作为斜拉桥重要的承重构件,经常发生振动问题。负刚度阻尼器具有优异的耗能能力,为拉索减振提供了新的选择。随着拉索长度的增加,需要的支撑高度也相应增加,从而可能引入一定的柔性。依托某实际斜拉桥建立支撑—负刚度阻尼器的数值模型,首先进行模型试验验证,并建立拉索控制系统数值模型;然后,考虑支撑的柔性来研究控制方案的设计参数,通过数值模拟来识别附加模态阻尼比。研究结果表明,建立的支撑—负刚度阻尼器数值模型与试验结果吻合较好,可以准确预测系统的力学行为;在柔性支撑条件下,可以采用较小的阻尼系数和负刚度水平,实现同等效果减振,即实现负刚度阻尼器的经济设计。

Cable-stayed bridges is a common form of large-span bridges,with stayed cables playing a crucial role as load-bearing components.However,these cables often suffer vibration issues.Negative stiffness dampers exhibit excellent energy dissipation capabilities,providing a novel option for cable vibration mitigation.As the length of the cables increases,the required support height also increases,potentially introducing some flexibility.Firstly,based on an actual cable-stayed bridge,a numerical model of the support-negative stiffness damper system is established and validated through model experiments.A numerical model of the cable control system is then developed.Subsequently,considering the flexibility of the support,the method for determining the design parameters of the control scheme is investigated,and numerical simulations are conducted to identify additional modal damping ratios.The research findings indicate a good agreement between the established numerical model of the support-negative stiffness damper system and experimental results,allowing for accurate predictions of the system's mechanical behavior.The use of flexible support enables the adoption of smaller damping coefficients and negative stiffness levels,achieving equivalent vibration reduction effects and thus facilitating an economically efficient design of negative stiffness dampers.