Program Development And Validation Of Vehicle-bridge Coupling Vibration With Grillage Method Based On Finite Element Model Updating

The vehicle-bridge coupled vibration is the result of interaction between vehicle system and bridge structure system. The former vehicle-bridge coupled vibration programs, which mainly target at single-girder model, can not simulate coupled vibration characteristics of bridge model with multi-girder and complex cross-section needed to be simplified with grillage method.Thus, it is necessary to develop the vehicle-bridge coupled vibration program of multi-girder and grillage method.Finite element model developed by design parameters may be different from the real structure because of simplied premise, uncertainy of boundary conditions and error of construction. It leads to more difficult if we apply finite element calculated results to assess bridge condition and analyze vehicle-bridge coupling vibration. Therefore, there are huge impact on theoretical analysis and great value on practical application of the research of finite element model updating.In this paper, three diffrent bridges are taken as examples, several key problems on finite element model updating are researched systematically, and the reliability of self-developed vehicle-bridge coupled vibration program is verified. The main research contents are as follows:Firstly, the research features and the problems unsolved at present of finite element model updating techniques and analysis methods for vehicle-bridge coupling vibration are reviewed, and several key problems on finite element model updating are summarized.On that basis, the analysis modules of the vehicle-bridge coupling vibration with grillage method and full vehicle load of static experiment are introduced in detail, and vehicle-bridge coupled vibration program is developed.Secondly,based on the optimization method parameter sensitivity analysis method, the experimental data collected on the spot are used to establish the objective function included different static and dynamic information.And the finite element models of three different bridges are updated.The influences of the different optimization methods, the different objective functions and the different boundary conditions are studied,and the difference of updating procedure as well as updated results are discussed and analysed in detail.Thirdly, the updated finite element model is as a benchmark model for the self-developed vehicle-bridge coupled vibration program, and the measured responses under static and dynamic loading cases, the calculated values in program and ANSYS are examined and compared omprehensively in order to validate the reliability of the static and dynamic analysis modules.