Structural Dynamics Model Updating Based On Substructure Synthesis Method

Model updating is modifying the finite element model based on test results. The purpose is to make the results of the finite element model of modified to approach test results. Large number of degrees of the finite element model lead to low computation efficiency. Component mode synthesis method is an effective way to deal with such problems. This paper is based on free-interface component mode synthesis method and studies the wing structure of model updating. The content is listed below:1) This paper discussed the basic idea of the model updating method and component mode synthesis method, and also described the basic principles of correlation between finite element model and test model and several degrees reduction method. Moreover, this paper described several classic element model updating methods.2) The paper proposed an improved free interface component mode synthesis method and derived a detailed theoretical basis of the method. The numerical examples show that the component mode synthesis method can significantly improve the operation efficiency, and has high calculation accuracy.3) The paper described the dynamics of the unit matrix perturbation theory and introduced the free interface modal synthesis method, derives the perturbation comprehensive equation of sub-structure and modal parameter. All the work had laid a solid preparation for sensitivity analysis of the eigenvalues during wing model modification.4) Based improved free interface component mode synthesis method, dynamic response analysis was conducted with MATLAB. A proper design variable and target function was chosen to able the model updating using the grade of sub-structure eigenvalues. The optimized value was reached after multiple iterations. The comparison of model updating method in the paper and model updating method of the whole wing structure validated the effectiveness of the method proposed in this paper.