Predicting Galloping Amplitudes: II

Abstract

The application of wind tunnel data to the calculation of vibration amplitudes includes the effect of structural damping. The linear theory is also reviewed and compared to the nonlinear theory. the asymptote for a vibration limited only by aerodynamic drag is approached when the system damping is near zero. The limit cycle predicted by theory is compared with the limit cycle found in wind tunnel tests. The agreement is good. Additional effects of span distribution are identified for further study. The role of mechanical system damping is shown to diminish as the wind speed increases above the critical wind speed. The critical wind speed is the same no matter which theory, linear or nonlinear, is used. an approximate describing function is introduced in closed form, which is based on maximum lift and lift reversal angle.