MR阻尼器在风雨激振的斜拉索中的减振应用

在考虑拉索垂度等条件下建立了拉索的风雨激振空间力学模型。在假设水线简谐运动,其频率和拉索一阶频率相等的条件下,得到了拉索在不加阻尼器的情况下距顶端1/2处和3/4处的面内、面外位移响应以及它们的幅频曲线,从而得出拉索主要是以单模态振动,且面内振动是安全的主要威胁。选用一对MR阻尼器对斜拉索进行减振,研究了模态阻尼比和阻尼器安装位置以及电压的关系,得到了拉索振动平稳后的位移响应。结果表明模态阻尼比存在最优电压值,而当阻尼器安装位置较高时,具有较好的减振效果。

THE APPLICATION OF MR DAMPER IN RAIN-WIND-INDUCED VIBRATION REDUCTION OF STAYED CABLE

Three-dimension model for rain-wind-induced vibration of stay cable is established, in which the lag of stay cable is considered. Based on the assumption that the motion of rivulet is harmonic and tts frequency is equal to the first modal frequency of stay cable, the in-plane and out-of-plane displacement response at the 1/2 length and 3/4 length from the top of stay cable, and their amplitude-frequency curves are obtained. The results show that the vibration of stay cable is mainly single-mode vibration. In-plane vibration is the chief danger to the safety of stay cable. Two MR dampers are applied for vibration mitigation. The relations among modal damping ratio and voltages and the location of the dampers are investigated. A segment of displacement response when it achieves stationarity is obtained. It’s shown that the modal damping ratio has an optimization voltage, and the effect of vibration mitigation will be better when the location of dampers is a bit higher.