Estimation of wind-induced responses of large membrane roofs including the nonlinear motion-induced aerodynamic forces

The effects of nonlinear motion-induced aerodynamic forces on the dynamic responses of large-scale membrane roofs are studied. These forces are from the nonlinear aerodynamic damping and linear aerodynamic stiffness. The responses are analytically obtained using an equivalent nonlinear approach. The characteristics of these responses, including the root-mean-square response, kurtosis, probability density function, peak factor, and peak response are analyzed. The response time history of large-scale membrane roofs under strong wind loads obtained from the nonlinear equation of motion of the structure with the fourth-order Runge-Kutta method is compared with the analytical solution. The proposed analytical approach is shown accurate and effective. Results indicate that the vortex-induced vibration of the roof in the high reduced velocity range is greatly influenced by the negative aerodynamic damping. The dynamic responses in the low reduced velocity range are mainly influenced by the negative aerodynamic stiffness with general buffeting behaviors. The proposed approach will contribute to a more economical preliminary design of such structures under strong winds.