Study on the characteristics and mechanisms of the wind-induced vibration of micro-elliptical section stay cables
Qingkuan Liu, Yifei Sun, Yaya Jia, Wenyong Ma, Bin Xiao
Abstract
Based on the statistical results of field investigations of stay cable shapes, the deformed cross-sections tend to be micro-elliptical. These deformations may significantly influence the aerodynamic forces and vibration characteristics of stay cables. Accordingly, the aerodynamic forces and wind-induced vibrations of stay cables with circular and various micro-elliptical sections are measured in wind tunnel tests. Furthermore, the influences of the Reynolds number, attack angle and major-minor axis ratio on wind-induced vibration are investigated. The aerodynamic damping is calculated based on the quasi-steady assumption to predict the observed vibrations. The results indicate that, compared with circular cables, cables with micro-elliptical sections generate larger-amplitude vibrations at certain Reynolds numbers and attack angles. Furthermore, large-amplitude vibrations occur mainly in the critical regime corresponding to Reynolds numbers of 2.5 × 105–4.0 × 105 and attack angles of α = 10°–30° and α = 60°–80°. However, the method based on the quasi-steady assumption is invalid for predicting wind-induced vibrations in the critical regime.