The Study Of The Vortex Resonance Characteristic On Typical Blunt Girder Cross-section

Low-damping, long-span, slenderness, light weight, small stiffness is the main trend ofbridge-engineering. The dynamic response of the bridge structure or components challengesthe engineering and wind engineering.Through the efforts of several generations, theaeroelastic problem of flutter and galopping as the most damaging wind vibration are basicllyunder control. Theory of wind resistance design can ensure that the critical wind speed ishigher than the natural bridge structure of the bridge.The vortex-induced resonance of thegirders, arch bridge suspender and bridgetower with low wind velocity is common.Vortex-induced resonance is a limiting vibration, but the amplitude of the reciprocatingmotion can seriously affects the fatigue of the bridge structure or components, alsomeasurements the strength and stability of the bridge.It can also affect the security and thecomfort of the construction machinery, the driver and the Pedestrian. These features show thesignificance of vortex-induced vibration research. In recent decades, it’s experience thatleading the vortex-induced vibration controlling in practical engineering. Engineers frequentlyconduct large-scale trial relying on existing solution of aerodynamic supression measure thathad been successfully applied by other bridge. Vortex-induced vibration is sensitive to manyfactors, and it’s extremely complex. Engineers of the operation is very clumsy. If knowingwhich parts of vortex-affecting region conrtolling the work of wind vibration, then targettingimproving the corresponding area of the section. It certainly will do more for less.Based on the particular typical bluff cross-section, gathering the pressure time historydata and acceleration data through the wind tunnel test of section model, then analysingdetailly related parameter values including vibration displacement amplitude, air pressurecoefficient of pulse value, predominant frequency of the power spectral density values, phasespectrum values, etc. This paper illustrates the key areas excited by the periodic sheddingvortex of boundary layer by the way of the time domain and the frequency-domain. Based thewind speed response of different angle of attack with the bluff section, the verticalvortex-induced vibration mechanism is revealed. Depending on the wind speed response Inthe form of different ventilation rail of the bluff section in this paper, the torsionalvortex-induced vibration mechanism is made clear.