Nonlinear Parametric Resonances in a Stay of the Iroise Cable-Stayed Bridge: Analytical Model and Experiments

Recent experimental campaigns led on the Iroise cable stayed bridge near Brest, France, revealed repeated vibratory events in some cable stays likely to provoke durability problems. A spectral analysis emphasized two regimes in which either the fundamental or the third cable mode were excited. Yet, wavelet scalograms of tests allowed to exhibit a global pylon mode excited by traffic environment through deck-cable-tower interaction and which again excites local cable modes by means of a nonlinear parametric resonance mechanism with vertical bending modes of the girder. Preliminary results are introduced as an attempt to explain such a scenario.Copyright © 2007 by ASME