Mechanisms and mitigation of bridge stay cable vibrations

风等环境因素引起的斜拉索振动是斜拉桥的一个当代问题。在过去的几十年里，这种类型的结构的跨度长度的增长导致更长和更灵活的电缆。这一点，加上其固有阻尼低，使电缆振动近年来成为一个更严重的问题。尽管人们已经更好地理解了与不同类型的拉索振动相关的机制，并且已经提出了各种控制方法并在真实的桥梁上实施，但在了解拉索行为的动力学和空气动力学方面，无论是否补充了不同的振动抑制对策，仍然需要做很多工作。 该研究计划旨在解决当今斜拉桥设计中一些最紧迫和最关键的问题。目标是：研究拉索-桥面相互作用对外部阻尼器抑制拉索振动效果的影响;研究拉索振动时拉索与周围流场的流固耦合作用，以进一步阐明拉索风致振动的机理;以及d）在结构工程和风力工程领域对HQP进行适当的培训。

Vibrations of bridge stay cables due to environmental factors like wind is a contemporary issue in cable-stayed bridges. In the past few decades, the growing span length of this type of structure led to longer and more flexible cables. This, combined with their low inherent damping, renders cable vibrations a more serious problem in recent years. Though mechanisms associated with different types of cable vibrations have been understood better, and various controlling methods have been proposed and implemented on real bridges, much is still needed in appreciating the dynamic and aerodynamic aspects of cable behaviour with and without the supplementation of different vibration suppression countermeasures. The proposed research program aims at resolving some of the most urgent and critical issues in the cable-stayed bridge design today. The objectives are: a) to develop a probability-based model for predicting dynamic response and assessing safety level of an externally damped bridge stay cable; b) to study the impact of cable-deck interaction on the efficacy of external dampers in suppressing cable vibrations; c) to investigate the fluid-structure interaction between an oscillating cable and its surrounding flow field for further clarification of wind-induced cable vibration mechanisms; and d) to achieve proper training of HQP in the areas of structural engineering and wind engineering.