Un modello di vorticità per l'analisi della stabilità aeroelastica dei ponti di grande luce con impalcato multiplo (in Italian) - A vorticity model for the aeroelastic stability analysis of long-span bridges with multi-box girder

In this paper a mathematical model for the aeroelastic stability analysis of multiple-deck long-span bridges is presented. The proposed model is based on the vortex concept of classical two-dimensional potential flow theory. In detail, for each deck beam cross-section a single potential vortex and, as a consequence of the section oscillation in the cross-wind flow, a wake distributed one are related by the Hemholtz condition. The model is first developed for a single-deck bridge cross-section in order to allow comparison with the Theodorsen's thin airfoil theory. Then, it is extended to the case of twin- and triple-deck bridge cross-sections. The comparison in real cases between the binary-flutter critical conditions obtained via present model and the available experimental data shows a good agreement.