A Mathematical Model of Nonlinear Aerodynamic Damping for High-Rise Buildings

Abstract

Vortex-induced vibration (VIV) is a critical problem for high-rise buildings. Thus, accurate prediction of aerodynamic damping becomes a key problem in the wind-resistant design of high-rise buildings. A common feature of the existing aerodynamic damping models is that most of their model parameters are functions of wind velocity. Such a feature leads to the inconvenience of users because the parameters need to change from case to case. This paper proposes an aerodynamic damping model that is a function of structure responses only. That means it does not need to adjust its parameters in different wind speeds. A single-degree-of-freedom aeroelastic square section high-rise building model with different structural damping ratios is tested in a wind tunnel for the analytical modeling. According to the identified aerodynamic damping coefficients and its relation with response amplitudes, the nonlinear aerodynamic damping model is proposed. It is a polynomial-type function of the instantaneous velocity and displacement of the structure. The results show that predicted responses, by using one set of model parameters, are in good agreement with the experiment data in the whole tested wind speed range. These results suggest that the proposed aerodynamic model can be a generic model for prediction of wind-induced vibration.