Investigation of Coupling between External and Parametric Resonances in Small Sagged Inclined Cables

The coupling between parametric and external resonances in inclined cables subjected to a motion of an anchorage with components both along and perpendicular to their axis is investigated. Besides posing theoretical challenges, this problem is of practical interest for inclined cables of cable-stayed bridges and guyed towers. First, the state of the art on the subject of multi-modal interactions of cables with moving anchorages is summarized. Then, the proposed analytical model is presented, which is selected to be as simple as possible, but still suitable for capturing the coupling between the first and second eigenmodes, hence between parametric and external resonances. Next, two specific cases of the general model, in which no coupling appears, are studied in order to identify the intrinsic characteristics of external and parametric resonance, respectively. Finally, the coupling between the two instabilities is investigated, aiming at a better understanding of the interaction phenomenon and at formulating practical engineering guidelines. ha l-0 08 75 11 5, v er si on 1 21 O ct 2 01 3 Author manuscript, published in "Compdyn 2011, France (2011)"