斜拉索-粘性阻尼器系统动力特性分析的模态坐标法

Mode Coordinate Method for Analyzing the Dynamic Characteristics of Stay-cable Viscous Damper System

粘性阻尼器是抑制斜拉桥拉索振动的一种有效方式.设计拉索减振系统的一个关键步骤是确定斜拉桥-粘性阻尼器系统的等效阻尼比,因此提出了一种分析这一问题的模态坐标法.通过准确地选取第一振型的振型函数,只需50阶振型就可得到满意的效果.以一根实桥拉索的设计参数为例,应用本方法考察了各种因素对模态阻尼比的影响.

Using supplemental viscous dampers has been an effective measure for stay-cable vibration suppression of stay-cable bridges.The determination of the equivalent damping ratio of a stay-cable viscous damper system is the key step in the design of a vibration mitigation system.A mode coordinate method has been proposed to solve the problem in this paper.By assuming the mode function of the first mode skillfully,fifty modes are enough to get an excellent solution.Taking the designed parameter of a practical bridge stay cable for example,the paper discusses the influence of variable factors on its modal damping ratio by the proposed method.