A generalized gust factor technique for evaluating the wind–induced response of aeroelastic structures sensitive to vortex-induced vibrations

Abstract

This paper develops a unified procedure for dealing with gust-excited vibrations and aeroelastic phenomena on slender structures and structural elements in the framework of the Generalized Gust Factor technique. The structure is arbitrarily inclined and constrained, and excited on its fundamental mode. Galloping phenomenon is taken into account considering linearized effects only; vortex-induced oscillations are simulated through a nonlinear equivalent damping based on the classic Vickery and Basu approach. The effectiveness of the procedure is discussed and verified over a selection of circular-shaped structures, object of extensive experimental measures. The model proposed is fully suitable to reproduce the effective structural aeroelastic behavior, also in the synchronization region at lock-in. Large uncertainties, however, arise from the choice of the model parameters, on which the literature is still poor. Particular attention is devoted to the limiting magnitude (which governs the non-linear aerodynamic damping) and to the peak factor (which supplies the maximum response), both these quantities having a crucial role in the assessment of vortex-induced vibrations.