Controle de oscilações em pontes suspensas com o uso de atenuadores dinâmicos ajustáveis

Abstract

The work approach studies in the structural dynamic area, specially in the control of oscillations because to the wind`s action in suspension bridges. Suspension bridges are engineer constructions which can develop long spans, and that they can get almost 2000 meters long in the nowadays. Long spans, added with the low structural rigidity and noncutting transversal sections make these structures very susceptible to the phenomena such as flutter and off resonance. These phenomena were responsible by collapse of Tacoma Narrows Bridge in State of Washington in 1940. The ruin of Tacoma Narrows bridge stimulated many studies about aero elasticity, which it is an area structural dynamic. Some products of these studies become solutions to the oscillation problems, such as Tuned Dynamic Attenuators, which are the principal objective of this work, which is going to design the Attenuators to reduce the oscillation movements. There are many models of Attenuators, such as pendulum type, damper type, and spring mass type. This last model can be active, semi-active or passives, in which the basic difference between them is that the first and the second have some actuators, which can vary the attenuator parameters with the objective to raise your efficiency, compared to the passive types of attenuators. The author chose as attenuator model the spring mass system of passive type because of viability to simulation. As result, it had reduction of almost 80% in the amplitude of oscillation, among others important aspects to projector, such as flexibility in the choice of parameters.