부공력감쇠를 고려한 와류하중모델의 진동예측성능

Abstract

The negative aerodynamic damping is a very crucial parameter in estimating the vortex induced resonance(VIR) in the across-wind direction. Aerodynamic damping is a major factor constituting so-called motion induced load or feedback load, and it is also a tool to explain the rapid manifestation of VIR. In this study, a mathematical model of aerodynamic damping are evaluated, and a process for predicting vortex induced vibration(VIV) along with vortex induced load model is proposed. By performing aeroelastic model test of a slender structure with a rectangular section, the aerodynamic damping and vortex-induced load are identified from the measured acceleration, based on these results, the mathematical models for aerodynamic damping and vortex induced load with respect to the wind speed were constructed. Finally, vibration estimation performance was evaluated by comparing the measured acceleration with the acceleration response obtained through re-analysis using the aerodynamic damping model and the vortex induced load model. From the numerical results, it was found that mathematical model of across wind load model are able to reliably predict VIV with a high reliability.