The aeroelastic stability of a multi-body system is studied through a four-degree-of-freedom model, which describes the linearized section dynamics of particular suspended bridges with doubly-symmetric cross-section, subject to a lateral stationary wind flow. A multi-parameter perturbation solution, applied to the classic modal problem in internal resonance conditions, allows a consistent reduction of the model dimensions. Focus is made on the particular parameter region corresponding to the triple internal resonance among a global torsional mode of the deck and two local modes of a pair of hanger cables. The bifurcation scenario described by an aeroelastic stability analysis is featured by two dynamic instability boundaries, strongly interacting to each other. The analysis of the critical wind velocity provides satisfying engineering results, pointing out how the presence of resonant light cables and the addiction of dissipative couplings, simulating passive viscous dampers acting on the cable-deck differential velocity, may have beneficial effects in preventing the aeroelastic instability of the multi-body system.

"Passive control of the aeroelastic instability of a symmetric multi-body sectional model"

LEPIDI, MARCO;PICCARDO, GIUSEPPE
2013

Abstract

The aeroelastic stability of a multi-body system is studied through a four-degree-of-freedom model, which describes the linearized section dynamics of particular suspended bridges with doubly-symmetric cross-section, subject to a lateral stationary wind flow. A multi-parameter perturbation solution, applied to the classic modal problem in internal resonance conditions, allows a consistent reduction of the model dimensions. Focus is made on the particular parameter region corresponding to the triple internal resonance among a global torsional mode of the deck and two local modes of a pair of hanger cables. The bifurcation scenario described by an aeroelastic stability analysis is featured by two dynamic instability boundaries, strongly interacting to each other. The analysis of the critical wind velocity provides satisfying engineering results, pointing out how the presence of resonant light cables and the addiction of dissipative couplings, simulating passive viscous dampers acting on the cable-deck differential velocity, may have beneficial effects in preventing the aeroelastic instability of the multi-body system.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11567/631850
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