An improved flutter derivative identification algorithm based on free vibration method
An improved hierarchical traversal iterative algorithm is proposed based on the global least squares method to improve the reliability of extracting characteristic parameters and flutter derivatives in the bending-torsion coupling time-domain response of the main beam.The flutter derivative and the eigenmatrix of the ide-al plane model are derived based on the Theodorsen theory.The characteristic parameters are solved to estab-lish the ideal displacement time-history data using the state-space method and realize parameter identification.The robustness of the hierarchical traversal iterative algorithm is tested using random incentive disturbance sig-nals and harmonic disturbance signals.The practicality of this algorithm is verified by main beam segment model vibration testing.The results indicate that the hierarchical traversal iterative algorithm has low initial value requirements.The characteristic parameter identification errors are less than 0.2％in the sensitive zone approaching the flutter critical wind speed.For random excitation interference with the noise intensities within 5％and harmonic signal disturbances within 10％,the proposed algorithm can effectively extract signal char-acteristic parameters and reconstruct displacement time-domain curves.For the primary flutter related to truss rotation angles,the identification errors between the proposed algorithm and the modified unifying least-squares(MULS)method are less than 1.4％.
万方数据
维普
