Study On The Coupling Vibration Performance Of Vehicle-Bridge System

This thesis deals with the following aspects concerning the coupling vibration performanceof vehicle-bridge system.1.The important influencing parameters of vehicle-bridge vibration system were extractedafter combing bridge and vehicle as an interaction system. Then they were analyzed as a wholeand carefully. The parameters affecting vibration performances, such as model, velocity, quality,damping, and span, were studied by some concrete examples.2.The dynamic response under variable speed moving load of different initial velocity andacceleration, and magnification factors of mid-span deflection were mainly discussed. Theresults showed that the effect of velocity to bridge dynamic coefficient was complex, that is tosay, the larger the velocity, nor the more significantly the dynamic response. There was nolinear relationship between magnification factors of load under variable speed and uniformmotion and velocity, while they were showed as sine, the more velocity, the larger amplitude.3.Considering the invigorative function of bridge deck irregularities random, the bridgevibration response under the condition of uneven pavement was analyzed by legend. Finally theimpact coefficient was also studied. The results showed below. Firstly, the uneven pavementaggravated the bridge vibration. The dynamic increment gave rise to peak changed withwavelength as a result of resonance in coupling system. So the smoothness of pavement shouldbe controlled and avoided resonance to decrease dynamic increment in bridge design andconstruction. Secondly, the dynamic increment changed with velocity, nor the linear increase.Peak formed at some velocity points because of resonance. If the velocity points in therealization range, it is necessary to monitor velocity points to the bridge amplitude. Thirdly, thedynamic increment also changed with span, and the peak formed when frequency of vehiclewas close to that of bridge. Additionally, the dynamic increment decreased with an increase ofspan. That's basically identical to the previous reports. The factors that influence impactcoefficient are very complex. Therefore, more research should be carried out on establishingsuitable amplified spectra of highway bridge load in China. A lot of vibration regularity achieved in this paper reflected the dynamic force andessential deformation of structure under the load of vehicle-bridge realistically. It's hoped thatthese results could provide reliable reference for engineering structuredesign and construction.