Mechanisms and mitigation of bridge stay cable vibrations

风等环境因素对斜拉桥斜拉索振动的影响是斜拉桥的一个当代问题。在过去的几十年里，这种结构的跨度越来越长，导致了更长的和更灵活的电缆。这一点，加上它们的低固有阻尼，使得电缆振动在近年来成为一个更严重的问题。尽管与不同类型的缆索振动相关的机制已经得到了更好的理解，并且已经提出并在实际桥梁上实施了各种控制方法，但在有无补充不同的振动抑制对策的情况下，仍然需要了解缆索行为的动力和空气动力学方面。

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.