Effect of fast frequency excitation on tower oscillations under turbulent wind flow

Abstract

In this paper, vibrations of a self-excited tower under turbulent wind flow, in the presence of a fast frequency excitation, are investigated and the corresponding equations of motion are derived. The nonlinear terms in the governing equation due to the simultaneous presence of the self, parametric and external excitation, are considered and the galloping phenomena of the tall cantilever structure is studied. It is demonstrated that fast excitations may shift the frequency response and delays Hopf bifurcation of the tower. For validation of analytical results, comparisons with numerical simulations are given for different kinds of excitations.