Codice  QDD 171 
Titolo  Torsional instability in a fishbone model for suspension bridges 
Data  20140120 
Autore/i  Berchio, E.; Gazzola, F. 
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Abstract  We consider a mathematical model for the study of the dynamical behavior of suspension bridges. We show that internal resonances, which depend on the bridge structure
only, are the origin of torsional instability. We obtain both theoretical and numerical estimates of the thresholds of instability. Our method is based on a finite dimensional projection of the phase space which reduces the stability analysis of the model to the stability of suitable nonlinear Hill equations.
This gives an answer to a longstanding question about the origin of torsional instability. 
