Finite element model updating of a blade swing mechanism based on response surface method

In order to improve the correlation between the results of modal analysis and modal test for a blade swing mechanism, a multiple parameters optimization was brought into updating the finite element model by using the response surface method. The overall modal parameters of the structure were extracted by the numerical modal analysis. And for this large assembly, a modal test was also developed by moving the sensor other than the hammer. The assurance criterion and the mode participation factor were made in use respectively to validate the test results and to confirm the main modes. Based on the finite element model error analysis, the model updating was carried out, using different material modification parameter at different part of the structure. The sample space was calculated and determined by the central composite test design, and the regression analysis on the samples was achieved by use of the multiple objectives response surface method, where the model updating targets were optimized. Finally, the modified parameters were applied in a new modal analysis to validate the accuracy of the updated model. On this basis, the dynamic simulation results were compared with the actual test results. The results show that the correlation between the results of modal test and updated modal analysis is improved, the average frequency error of the first three modes is reduced from 9.71% to 0.73%, and the modal shape MAC is improved from 0.74 to 0.89. © 2016, Editorial Office of Journal of Vibration and Shock. All right reserved.