A novel fabrication method of the three-dimensional forced vibration system for high-rise buildings

The forced vibration wind tunnel test is widely used to estimate the aeroelastic effect of high-rise buildings due to its ease of fabrication and reliable identification of the aeroelastic parameters. However, most traditional forced vibration systems (FVSs) can only realize one-dimensional (1D) or two-dimensional (2D) vibrations at most, and the structural model can only simulate linear or constant mode shapes. The present study proposes a novel three-dimensional (3D i.e., two translational and one torsional vibrations) FVS that can drive the model to vibrate in 3D while maintaining more realistic mode shapes. Employing the proposed 3D FVS, the amplitude, frequency, and phase angle of the model's 3D vibrations can be adjusted independently. Then, the resultant motions of the model are measured by three laser sensors to examine the performance of the system. Results show that the proposed system performs well, providing stable vibration amplitude, frequency, and phase angle in all the three directions. Finally, making use of the 3D FVS, the significant differences between the results of 3D forced vibration and 1D forced vibration are uncovered, in terms of power spectrum density (PSD) of wind forces on the model and the associated aerodynamic stiffness and damping ratios. The proposed system, therefore, provides an alternative of wind tunnel test methods for determining the aeroelastic properties of high-rise buildings.