Study On Wind - Vehicle - Bridge Coupled Vibration

The wind- vehicle-bridge space coupling vibration can be understood as: the interaction of wind and car, car and bridge, the fluid-structure interaction of wind and bridge, and the interaction between these three.There are many factors that affect the interaction including the nature of the wind property, the dynamic characteristics of the bridge, and the vibration of the vehicle performance.To understand the interaction, the first thing is to delve into its influence factors, This article mainly carried out a research into the following several aspects.First, the wind- vehicle- bridge coupling study need to compute the buffeting force by wind on the bridge, but the buffeting force is closely related to the fluctuating wind, it is caused by fluctuating wind, so it is very important to get the wind speed spectrum function by observing the wind environment of bridge site.To this end, the team carry out a year-long observation of the wind environment in Cun Tan Chang Jiang river bridge site, the author used the time-domain wind speed data observed to carry on the fast discrete Fourier transform to get the wind speed spectrum values, and get the preliminary wind environment wind spectrum function by the least squares fitting.However time-domain buffeting calculating needs to know each node of girder horizontal and vertical fluctuating wind speed, and, it is not possible to do this in to this in the actual wind environment observation, To this end, the author developed three-dimensional fluctuating wind field simulation program SWFCMN according to the improved harmonic synthesis method. Using the program, we can obtain the vertical and horizontal fluctuating wind program of each nodeas long as a given wind spectrum function and bridge node coordinates.Another important factor influencing the buffeting force is aerodynamic admittance, therefore Therefore we carry out wind tunnel experiment of the wide-body beach bridge box girder section model of Cun Tan Yangtze river bridge to gain coefficient of three component, the author used measured wind speed and buffeting force to carry on the fast discrete Fourier transform to get the wind speed spectrum and power spectrum,and then on the basis of the value fitting out aerodynamic admittance function, all analysis.Second, builded the common vehicle vibration mechanics models, analyzed the incentive of bridge on wheels can be considered as comprehensive pavement roughness, gived the concept of comprehensive road surface roughness. the author developed the simulation of the road surface roughness programe LMPZD based on MATLAB platform, By using this program, the auther simulated three kinds of road surface roughness named A, B, C and compared the result with the spectrum values, the it is perfect.On this basis, presents a separate iteration principle to calculate Vehicle- bridge coupling and coordination and the boundary conditions.Finally, introduce the method of program development of The wind- vehicle-bridge coupling based on Separate iteration method. Wind- car- bridge coupled.the author used the APDL secondary development platform of ansys to developed wind-vehicle- bridge coupling calculation program according to the principle of separation of iteration method. Introducing one of the application of wind- car- bridge coupled vibration: The safety evaluation of driving.Establishing the evaluation model of three safety accident, giving the critical reference wind speed of the vehicle control of Cun Tan Yangtze river bridge.The calculation results of Bridge buffeting response show that the aerodynamic admittance function has much effect on the buffeting force. The result of considering the nonlinear and does not considering nonlinear is very significant, it shows that large span suspension bridge is flexible, the nonlinear effects cannot be ignored.The wind- vehicle- bridge calculation shows that the aerodynamic performance of different vehicles is completely different, The critical wind speed of safety accidents is also different.