Wind loads on a super-tall slender structure: A validation of an uncoupled fluid-structure interaction (FSI) analysis

Abstract

Abstract: The paper presents a numerical validation for an innovative and time-efficient uncoupled fluid-structure interaction (FSI) method used to evaluate structural responses of super-tall structures. An aeroelastic multi-degree of freedom (MDOF) model of a super tall structure was tested in a boundary layer wind tunnel (BLWT) where tip displacements and acceleration were recorded and compared with a numerical simulation. A validated computational fluid dynamics (CFD) numerical simulation was performed to obtain wind-induced pressures in the numerical analysis. The novelty in this study lies in the mechanism that these wind pressures are communicated to the structural model in an efficient manner, to obtain structural responses. An innovative numerical technique is used to convert the wind-induced pressures on the building surface to nodal time history loads, which were then used to perform an implicit modal analysis to obtain the structure's time history response. The proposed new method was shown to perform in 240 s of clock time and could provide similar numerical accuracy to that of the experiments. Other important observations on the structure's response with regard to vortex-induced vibrations (VIV), the impact of aerodynamic damping and structural damping on the performance of the structure are critically evaluated and discussed herein. Finally, it was demonstrated that the presented numerical method could be used as an alternative to full aeroelastic wind tunnel studies to efficiently obtain structural responses of super-tall structures.