Finite Element Model Updating Based On Frequency Response Function And It's Software Realization

In the dynamic design of structures in the aerospace,automotive and marine engineering fields,finite element models are widely used,mainly including structural response prediction,optimization design,reliability analysis,fault diagnosis,and damage detection.Therefore,high-precision finite element Models matter.With the improvement of the accuracy requirements of the finite element model,the finite element model updating technology has also been developed,which has become one of the important research directions in the field of structural dynamics.This paper focuses on the FEM model updating technology based on the frequency response function,and deduces the model modification method based on the frequency response function in detail,the solution of the frequency response function,the derivation of the sensitivity matrix and residual equation,the correlation analysis,and the correction quality detection And other issues were elaborated.Based on the updating theory,a model updating software based on frequency response function was developed,and the correction module was effectively combined with general software.Aiming at some key problems in model updating based on frequency response function,the developed model updating software and finite element simulation examples are used for research and discussion.Aiming at the problem of finite element modeling,a fully parameterized concept was proposed,and its effectiveness was proved with GARTEUR aircraft examples.Several methods for selecting parameters to be modified and principles for selecting frequency points were summarized.The example validates the validity of the method of parameter selection based on sensitivity analysis and the principle of frequency point selection;the feasibility of model updating under incomplete experimental data is verified by simplified truss structure simulation examples.Finally,this paper conducts vibration experiments on the beam structure,and uses the frequency response function-based model updating software to modify the finite element model of the beam structure to study the effectiveness and engineering practicability of the software.The results show that the software has a certain engineering application value.