Ricerc@Sapienza

This research deals with the effects produced by aerodynamic appendices on the aeroelastic stability of long-span bridge decks. A simulation model is presented by which the structural motion and the fluid flow are together and simultaneously simulated. The deck is schematised as a bidimensional two-degree-of-freedom rigid oscillator, whilst the aerodynamic fields are simulated by numerically solving the 2D Arbitrary Lagrangian-Eulerian (ALE) formulated Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations on moving meshes which adjust to the deck motion.

We study Winter or delta-shell model at finite volume (length),
describing a small resonating cavity
weakly-coupled to a large one.
For generic values of the coupling,
a resonance of the usual model corresponds,
in the finite-volume case,
to a compression of the spectral lines;
for specific values of the coupling,
a resonance corresponds instead to a
degenerate or a quasi-degenerate doublet.
A secular term of the form g^3 N
occurs in the perturbative expansion
of the momenta (or of the energies)