Method for Decoupling and Correction of Dynamical Signals in High-Frequency Force Balance Tests

High-frequency force balance (HFFB) technology is a popular experimental method for investigating dynamic wind loading and wind-induced response of high-rise buildings. A decoupling matrix obtained from static calibration is provided along with HFFB when leaving a factory. This matrix is used to achieve the conversion from voltage to measured signals. The static component can actually be decoupled but the dynamic component generated by the balance-model system (BMS) cannot be decoupled fully. Thus, the dynamic distortion signals caused by the dynamic amplification of BMS cannot be corrected effectively. A general approach is proposed to decouple and correct the coupled dynamical signals in HFFB tests. The measured signals are initially decoupled by the complex blind modal identification (CBMID) technique. Subsequently, the modified Bayesian spectrum density approach is adopted to identify modal parameters effectively, and the distortion components of modal signals are corrected according to the identified parameters. Finally, the base aerodynamic signals of BMS, whose dynamic amplification effect is eliminated, are synthesized by the mode shape obtained by using the CBMID method. The proposed method can automatically adapt to complicated test conditions, such as nonproportional damping or inhomogeneous material distribution and wind-structure interaction. Lastly, the HFFB wind tunnel test of a 528-m superhigh-rise building is taken as an example to indicate the validity and superiority of the proposed method. (C) 2018 American Society of Civil Engineers.