DESIGN OF MECHANICAL VISCOUS DAMPERS FOR STAY CABLES
DESIGN OF MECHANICAL VISCOUS DAMPERS FOR STAY CABLES
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DOI：
10.1061/(asce)1084-0702(2000)5:2(114
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发表时间：
2000-05
影响因子：
3.6
通讯作者：
H. Tabatabai;A. Mehrabi
中科院分区：
文献类型：
--
作者：
H. Tabatabai;A. Mehrabi
外部阻尼器已被用于一些斜拉桥，以抑制横向索振动。然而，简单而准确的阻尼器设计建议，同时考虑所有重要的电缆参数是缺乏的。以前的努力是基于理想化的电缆作为绷紧的弦。本文将含粘滞阻尼器拉索振动的控制微分方程转化为含无量纲拉索参数的复特征值问题。接下来，进行参数研究，涉及范围广泛的无量纲参数的本征值问题的重复解决方案。阻尼器对第一模态振动频率和第一模态阻尼比的影响以无量纲形式给出。结果表明，对于大多数斜拉索中涉及的参数范围，拉索垂度的影响是微不足道的，而拉索的弯曲刚度可以产生显着的影响所产生的拉索阻尼比。简化的无量纲关系，提出了计算阻尼器引起的第一模式的电缆阻尼比的变化。在一个比例模型电缆的实验室测试结果进行了比较，估计值使用的配方。例子的问题也提出了比较和设计的目的。
External dampers have been utilized in a number of cable-stayed bridges to suppress transverse cable vibrations. However, simple and accurate damper design recommendations that concurrently consider all important cable parameters are lacking. Previous efforts have been based on the idealization of cables as taut strings. In this paper, the governing differential equation for vibration of cables containing a viscous damper is converted to a complex eigenvalue problem containing nondimensional cable parameters. Next, a parametric study is conducted involving repeated solutions of the eigenvalue problem for a wide range of nondimensional parameters. The effects of dampers on first mode vibration frequencies and first mode cable damping ratios are presented in nondimensional format. It is shown that, for the range of parameters involved in most stay cables, the influence of cable sag is insignificant, whereas the cable bending stiffness can have a significant influence on the resulting cable damping ratios. Simplified nondimensional relationships are proposed for calculating damper-induced changes in the first mode cable damping ratios. Results of lab tests on a scaled model cable are compared with estimated values using the formulation presented. Example problems are also presented for comparison and design purposes.