Study On Spanwise Correlation Of Vortex-Induced Force Of A Streamlined Closed Box Girder

This thesis introduced vortex-induced vibration of bridge at home and abroad,and VIVresearch actuality was summarized in detail,then correlation of Vortex Shedding Force wasstudied based on wind tunnel experiments and numerical simulations.The main contents ofthis thesis are as follows:1.Based on Scanlan’s empirical linear model,Scanlan’s nonlinear model and Larsen’sgeneral model,The corresponding model aerodynamic parameter identification procedurewere written.2.Vortex-induced vibration lock-in range and decay curve of different amplitude wereobtained through section model wind tunnel test of JiangShun Bridge.The aerodynamic pa-rameters of the vortex-induced force model in the lock-in of different amplitude were identi-fied using three methods of semi-empirical model and their identification accuracy werechecked.3.Based on the brief introduction of the state-of-the-art of spanwise correlation of vor-tex-induced force,the pressure measurement wind tunnel tests of VIV of the main deck of Ji-angshun bridge were conducted. The results show that,Vortex-induced force correlation coef-ficients increase with the amplitudes increase,however,the correlation coefficient of Vor-tex-induced force is not maximum when the VIV amplitude gets maximum.The spanwisecorrelation coefficients of Vortex-induced force are influenced differently with the amplitudein left half and right half of the vortex shedding lock-in.4.Numerical simulation of VIV of the cyciliners with circle section,πsection andstreamlined closed-box section of Jiangshun bridge separately were conducted with the soft-ware of FLUENT.The nulerical results of lock-in range and vibration amplitude agree wellwith wind tunnel test results.ICEM was used to establish three-dimensional model of JiangShun Bridge and six rows of pressure taps were placed along the model.Numerical simulationof flow around the stationary streamlined closed-box girder was conducted.The numerical re-sults show that the3D numerical results of the aerostatic coefficients of the streamlinedclosed-box girder of agreees well with the results of2D numerical results The spanwise cor-relation coefficients of lift and torque decrease with the spanwise length,and the correlationcoefficients of lift are larger than the correlation coefficients of torque of the streamlinedclosed-box girder.