Research On Finite Element Model Updating Method Based On Error Location

In daily study and work,the difference between the established finite element model and the actual structure is too large,which can not meet the needs of modeling.In order to solve this problem,the actual model is tested first,and the finite element model is adjusted with the experimental data,so as to reduce the difference between the finite element model and the actual structure.According to the different objects,the finite element model updating technology can be divided into two types: matrix updating method and parameter updating method,among which the parameter updating method has more engineering value.The most critical part of parameter correction method is the selection of correction parameters.Usually,the parameters with higher sensitivity should be selected as correction parameters,but this does not mean that the parameters with higher sensitivity can be used as correction parameters.In short,high sensitivity is a necessary condition rather than a sufficient condition for the correction parameters,so it is necessary to use other methods with sensitivity analysis to select the correction parameters.Firstly,this paper introduces the technology of degree of freedom matching and correlation analysis,and describes its specific application.The orthogonal model orthogonal mode(CMCM)model correction method is improved and applied to error location.The error location ability is compared with two traditional damage detection methods.It is proved that the improved CMCM method not only has better positioning error ability,but also has less influence on it due to the incompleteness of modal data.In order to verify the engineering value of the improved CMCM method for error location,the error location of the cantilever beam with mass block and a flexible spacecraft are carried out,and the final positioning effect is good.Combined with sensitivity analysis,it is found that there is no parameter with very low sensitivity in the CMCM method,but the parameter with higher sensitivity is very accurate,which also proves the practicability of the improved CMCM method in error location.With the help of error location and sensitivity analysis,the network structure can be designed and trained according to the correction parameters and the required modal parameters.Finally,the test data are input into the trained network to solve the correction parameters.