Application scope of equivalent linear technique for across-wind response analysis of tall flexible structures considering nonlinear aero-elastic effect. (1st April 2023)

• Record Type: Journal Article
• Authors: Guo, Kunpeng; Yang, Qingshan; Hui, Yi; Shan, Wenshan; Lupi, Francesca; Huang, Shuai; Hu, Weicheng
• Is Part Of: Journal of building engineering. Volume 64(2023)
• Publication Date: 2023-04-01
• Subjects: Non-linear effect -- Across-wind response -- Aerodynamic damping -- Tall flexible structures -- Equivalent linear technique; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2022.105678
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: Large across-wind response of tall flexible structures becomes an increasing concern due to the significant nonlinear aero-elastic effect. The nonlinear aerodynamic damping, which is in phase of time-variant structural velocity, is usually employed to describe nonlinear aero-elastic effect. For the sake of evaluating the across-wind response of tall flexible structures within the framework of linear random vibration theory, equivalent linear aerodynamic damping model is required, which can be deduced from either harmonic balance (HB)- or statistical linearization (SL) technique. This study addressed clarifying application scope of various equivalent linear techniques for evaluating across-wind response of tall flexible structures. By conducting the Monte Carlo simulation and free-vibration wind tunnel test, it is clarified that the root-mean-squared (RMS) response calculated by the HB equivalent linear aerodynamic damping is acceptable, while is not satisfactory with respect to the SL technique especially when the structure is with lower damping level, and in the vicinity of vortex lock-in wind speed. Moreover, it is found that neither HB- nor SL technique can accurately predict the peak response. It is revealed in this study that accuracy of various equivalent linear techniques is essentially affected by probability density function of across-wind response. Highlights: The generalized Van der Pol aerodynamic damping model is used to describe the non-linear effect of a crosswind-excited tall flexible structure. Application scope of various equivalent linear techniques for estimating the across-wind response of tall flexible structures is clarified. An underlying paradox concerning estimation of crosswind response by the equivalent linear aerodynamic damping along with the linear random vibration theory is revealed.