Research On Bird Impact Finite Element Model Updating Techinques Based On Optimization

Due to such merits as integrality, accuracy, and convenience to be programmed, the finite element method (FEM) has been avidly used in the engineering nowadays. While FEM model of structure is established, differences inevitably exist between the FEM model and the real structure model. The FEM model updating technology is used to correct the FEM parameters of structure in order to obtain more precise results. Some effective measures could update the FEM parameters of structure according to the test data.Because of the complexities of high-speed impact problems, especially great uncertainty of the material parameters of the bird, it is very difficult to precisely simulate the bird impact. The error finite element model is caused by the assumptions of modeling simplification, the approximate boundary conditions, and the error of physical parameters. Without a correct bird impact finite element model, there is larger deviation in the results.Based on above cognitions, the thesis mainly focuses on the theory and the application of the FE model updating technique based on optimization methods. In the thesis, the basic ideals and methods of FE model updating technique are presented. The systems of the bird impact experiment is introduced in detail, some factors that affect the accuracy of the FE model are analyzed,and the experimental results are used to update the bird impact FE model. The updated results and the experimental results are compared and analyzed. The research shows the feasibility and correctness of the method. Lastly, a bird impact simulation experimental database management system is developed. Lots of experimental data could be stored and used to analyze the experimental results to evaluate the results of the updated bird impact FE model. It provides a technical support for bird impact simulation platform and the application of the FE model updating technique.