dynamics and torsional stability of a new model for suspension bridges

DYNAMICS AND TORSIONAL STABILITY OF
A NEW MODEL FOR SUSPENSION BRIDGES
GIANNI ARIOLI
DIPARTIMENTO DI MATEMATICA
POLITECNICO DI MILANO
Abstract. In this talk I will discuss three topics:
1) a new model for suspension bridges consisting of two hyperbolic PDEs, one describing the
dynamics of the center of the deck, the other describing the torsional movement. All constants
are chosen to fit the old Tacoma Narrows bridge.
2) a detailed study of the torsionless periodic motions of such model.
3) the torsional stability of such periodic motions.
I will show that the periodic motions of small amplitude are always torsionally stable, but
each motion presents a threshold above which the torsional stability is lost. Such threshold
appears to be very close to the catastrophic dynamics occurred to the Tacoma Narrows bridge.
E-mail address: [email protected]
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