Evaluation of aerodynamic damping in full-scale rain-wind-induced stay cable vibration: Fid-Bau Portal

Evaluation of aerodynamic damping in full-scale rain-wind-induced stay cable vibration

Hua, Jieying / Zuo, Delong

Abstract Rain-wind-induced vibration of stay cables has been a long-standing problem for cable-stayed bridges. Despite the numerous full-scale and laboratory studies conducted to understand this phenomenon, a consensus on the excitation mechanism that causes the vibration has not been reached. As a result, although many types of formulation have been used to develop models for rain-wind-induced vibration, the capability of these models to effectively predict full-scale vibrations has not been definitively validated. Motivated by the qualitative similarities between the rain-wind-induced vibration and vortex-induced vibration observed in the field, this study proposes to model rain-wind-induced vibration as a Van der Pol oscillator in a manner similar to that used in the modeling of vortex-induced vibration by some previous studies. The model is used as a basis to evaluate the aerodynamic damping resulting from the interaction between the vibration of full-scale stay cables and wind as well as rain, which is the fundamental mechanism that causes large-amplitude vibrations. The dependence of the generalized coefficients representing the linear and nonlinear components of the aerodynamic damping on the characteristics of both the vibration and the wind is interpreted.

Highlights • Rain-wind-induced vibration is modeled as a Van der Pol oscillator with linear and nonlinear aerodynamic damping. • The aerodynamic damping in full-scale rain-wind-induced vibration is evaluated based on the model. • The dependence of the aerodynamic damping on the characteristics of the vibration and the wind is interpreted. • The critical structural damping for preventing the onset of rain-wind-induced vibration is estimated.