The Dynamic Response Analysis And Structure Optimization Study Of The Suspension Bridge

Along with the application of structure health monitor system in large span bridge, the finite element modeling of bridge structure and the analysis get more and more attentions. Establishing the accurate finite element model(FEM) of bridge is extremely important in the study of the large span bridge structure, such as static analysis, dynamic response analysis, optimization design of structure, the security health monitor and the damage appraisal, etc. This paper armed at a suspension bridge with orthogonal floorboard steel box girder, utilized parametric modeling method, established the more precise FEM of suspension bridge. Comparing the result of static analysis and modal analysis with the measured data, the accuracy of FEM can be confirmed.The action of the dynamic load is more significant in the bridge design and the maintenance In the last 20 years, there are great advancements in dynamic response analysis, especially in the study of motion load simulation, the moving-load-induced vibrations of bridge , the response of wind load, earthquake response as well as structure stability. The research target of this paper focused on the moving load response analysis and the steel box girder structure optimization of the suspension bridge.Through some analyses, computation and experiment, main completed works are as follows: Firstly, a steel box girder FEM with orthogonal floorboard was promoted, which can describe the steel box girder's whole and local properties accurately. This work also built a foundation for following research work.Secondly, this paper gives an analysis method about the moving load response analysis of suspension bridge with orthogonal floorboard steel box girder, and reveals the response characteristic of bridge.Thirdly, the paper proposed an idea of optimization of the steel box girder system, which took the structure weight (volume) as the optimized goal. The shape and the size of the girder were chosen as design variables, and the strength and deformation of the girder were taken as resistant conditions.Fourthly, as an example, some analyses and calculations about the Humen suspension bridge were presented. After setting up its FEM by the parameterization method, the moving load response analysis and the steel box girder optimized design of the bridge were achieved.Finally, contrasting the analysis results of FEM with the data of dynamic strain tests, the correctness of the analysis method and calculation result were proved. Furthermore, a response rule of suspension bridge under moving load was found.