The Analysis Method Study Of Finite Element Model Updating And Verification Of Blade For Vibration Characteristic Analysis

As the core component of engine, precise analysis of vibration performance plays a vital role in improving the strength and operating life of life. Consequently, model updating and verification will improve the precision of finite element model and provide more credible analysis results for the further analysis and computation of dynamic model.In this paper, natural characteristic analysis and response analysis of base excitation of the straight blade are given firstly, then the results of finite element analysis and experiments are obtained. Based on experimental data, a method of finite element model updating is proposed, this method gives correlation analysis on results and take the modal parameters as updating objects. Moeover, cubic spline interpolation is also introduced which palys a part in determine the optimal population of parameter. Finally, the contrast effect of model updating is shown and gives a verification on the feasibility and availability of this method.In this paper, the specific research contents are mainly divided into the following sections:(1) Based on test objectives, test method and test system are given respectively, then natural characteristic test and response test of base excitation of straight blade are conducted and corresponding test results which include the first ten natural frequencies and corresponding modes and response value are obtained.(2) Applying the finite element analysis software, initial finite element model of straight blade is established, then modal analysis and response analysis of base excitation are conducted and corresponding test results which include the first ten natural frequencies and corresponding modes and response value are obtained.(3) Based on natural characteristic analysis, a method of finite element model updating is proposed. This method regard the test results as reference data and gives the sensitivity factor value, then constructs objective function based on the first ten natural frequencies. Moreover, cubic spline interpolation is introduced which palys a part in determine the optimal population of parameter including material parameter, geometrical parameter and finite element model analysis parameters. Finally, by contrasting effect of model updating, the three dimensional histogram of correlation coefficient MAC are shown and the feasibility and availability of this method, is verified.(4) Based on response analysis of base excitation, a method of finite element model updating is proposed. This method regard the test results as reference data, gives the sensitivity factor value, and constructs objective function based on response value under different exciting frequencies and different excitation amplitudes of different test points. Moreover, cubic spline interpolation is introduced which palys a part in determine the optimal population of parameter including damping ratio, excitation amplitude and sweeping frequency precision. Finally, by contrasting effect of model updating, the scatter diagram of correlation coefficient MAC are shown and the feasibility and availability of this method, is verified.This paper proposes a method of finite element model updating based on natural characteristic analysis and response analysis of base excitation, it is of great significance to improve the accuracy and reliability of finite element analysis.