Theory of rain-wind-induced vibration of stay cables: A quasi-steady-state approximation

Abstract

Rain-wind-induced vibration (RWIV) of stay cables in cable-stayed bridges is jointly induced by rainfall and incoming wind. It is a major concern to the bridge engineering community due to its very large vibration amplitude. Yet the characteristics and mechanism of RWIV have not been understood completely. In particular, a theoretical model that can well describe the RWIV is urgently needed for amplitude prediction in engineering applications. Following a recent experimental work, we propose a theoretical framework for the analytical analysis of RWIV in the present study. The moving upper rivulet, which plays a crucial role in the excitation of RWIV, is modeled with a quasi-steady-state approximation. The analytical and numerical results are first compared with the experimental data to validate the theory. Then, the effects of some key parameters, including cable mass, frequency, damping ratio, and dynamic upper rivulet, on RWIV are investigated in detail with the theoretical framework. The model in the present study provides quick and reliable evaluations of the vibration amplitude and influencing parameters of RWIV, without performing time-consuming experiments in wind tunnel or computational fluid dynamics simulations.