考虑桥面运动的斜拉索减振模型

The characteristic of stay-cable damping system in consideration of bridge deck vibration

针对拉索减振模型未考虑桥面-斜拉索-阻尼器耦合振动的现状,提出适用于桥面运动的斜拉索减振分析理论模型,采用复模态分析方法对拉索-阻尼器系统的模态阻尼特性进行数值分析.结果表明,在桥面激励条件下,拉索-阻尼器系统的模态阻尼比与拉索的倾角有关,外部阻尼器相同时,斜拉索的倾角越小,系统的模态阻尼比越小.

The coupled vibration impact of the bridge deck-cable-damper is not reasonably considered in existing vibration models.In this study,a new analytical model is developed in order to investigate the coupling effects among deck-cable-damper.To investigate the affects of modal damping of the cable-damper system subjected to the coupling motion with the deck,the normalized damping ratio is calculated by a numerical process of the normalized damper coefficient for different support conditions.The result shows that the external damping should be greatly increased to provide the same non-dimensional modal damping with the decrease of the stay angle,and that existing models overestimated the value of the non-dimensional modal damping.The new model matches well with the actual occurrence in bridge engineering.