Research And Implementation Of Structural Dynamic Model Updating Based On Eigensensitivity And Genetic Algorithm

Dynamic finite element modeling is an integral part of the structural design. In orderto accurately predict the dynamic characteristics of the structure, finite element modelshould be updated according to the experiment data. Vibration equation of Structuraldynamic model has the characteristics of large dimension and high nonlinearity, whichbring great difficulties to the implement of dynamic finite element model updating.The method of correlation analysis and eigensensitivity analysis is introduced in thepaper, and also the mathematical model of the structural dynamic model updating is built.In-depth research is done on the process of model updating based on the eigensensitivity.Modal expansion and condensation, Parameter selection strategies and Solution ofill-posed equations are further discussed. And then the implement of model updatingalgorithm based on eigensensitivity analysis is also given in the paper.Taking into account the characteristics of great possibilities to fall into local minimaand high nonlinearity in the model updating method based on eigensensitivity analysis,Genetic Algorithm is applied to the structural dynamic model updating, and themicro-Genetic Algorithm is improved, combining with the characteristics of modelupdating. The tournament selection with parents’ competition and the simulated annealingselection strategy are adopted in the improved algorithm to ensure the high fitness andenough diversity of the generation. A case indicates that improved micro-GeneticAlgorithm has obvious advantage when applied to the structural dynamic model updating.On the basis of the two structural dynamic model updating theories recommendedabove, a prototype structural dynamic model updating system using MFC, HOOPS andIntel Math Kernel Library as the development platform is developed. According to theresearch of theory, the data structure of finite element model and updating manager isdesigned, and the structural dynamic model updating based on the eigensensitivity andGenetic Algorithm is achieved in the system.Finally, an example is applied to verify the functions of structural dynamic modelupdating system. The results show that the developed prototype system meets the basicrequirements of engineering applications.