Quasi-periodic galloping of a wind-excited tower under fast excitation and parametric damping

Abstract

This paper investigates the influence of combined fast external excitation and internal parametric damping on the amplitude and the onset of the quasi-periodic galloping of a tower submitted
to steady and unsteady wind flow. The study is carried out considering a lumped single degree of freedom model and the cases where the turbulent wind activates only an external excitation is studied. A perturbation method is performed to drive the slow flow dynamic near the primary resonance. The influence of fast excitation and parametric damping on the quasi-periodic (QP) galloping onset is explored. The results shown that the performance of the combined loading on retarding the QP galloping onset is better over the cases where the loading are acted separately.