Wind Induced Vibration of High-Rise Structures

Abstract

Stochastic dynamic responses of high-rise structures under turbulent wind is analyzed at two directions in this study. In particular, two types of structural configurations, namely, a mega-sub building and a TV tower, are considered. The wind speed consists of mean and turbulent parts. The turbulent part is idealized as a non-white stochastic process with spatial variation along the height of the structures. When the interaction between wind and structure is taken into consideration, the drag force represents the additive and parametric excitation with nonlinear colored noise, while the lift force the parametric excitation with nonlinear colored noise (updated Scanlan-Simiu model). Assuming that the wind direction is slightly off the direction normal to one side of the structures (the x-direction), it is shown that the x-direction vibration is generated primarily by the drag force due to the x-direction wind speed, while the y-direction vibration is generated primarily by the lift force exerted by vortex shedding resulting from the x-direction wind speed, and by the drag force due to the y-direction wind speed. With the aids of spectral representation method and numerical technique, the static and random vibration responses of the structures are then found for each simulated turbulent wind input. The response trajectories of the structures at specific heights are also derived. These results provide fundamentally important information for the vibration control analysis of the high-rise structures with passive and/or active mass dampers.