Research On The Identification Of Operating Mode Parameters And Model Updating Of Airframe During Ground Taxiing

The aircraft ground vibration test is to obtain the modal parameters of the aircraft,and the measured modal parameters provide the basis for aircraft structural dynamics modeling,aeroelastic calculation and flutter analysis,etc.Because the ground vibration test of the aircraft must be completed before the flight test of the aircraft,the test cycle is relatively short and the task is relatively heavy.In order to improve the test efficiency,shorten the test period and reduce the test cost,the modal data required to verify the aircraft finite element model must be obtained from other vibration tests before the aircraft ground vibration test.This article takes the internationally recognized GARTEUR aircraft model as the research object,and conducted the ground vibration test and the taxi vibration test research on the GARTEUR aircraft model with landing gear,and evaluated the feasibility of identifying the modal parameters of the airframe by the taxi vibration test.The finite element model is modified by the combination of the test and the numerical calculation,using the modal parameters measured in the taxiing vibration test.Firstly,taking the GARTEUR aircraft model with a landing gear as the research object,the GARTEUR aircraft model with a landing gear under the free-free state and the shutdown state uses the phase resonance / phase separation integration technology to identify the modal parameters.In the end,the ground vibration test obtained similar test results to those of foreign research institutes,indicating the effectiveness of the method used in this test.By comparing the test results in two states,the influence of different boundary conditions on the modal parameters of the GARTEUR aircraft model with landing gear was discussed.Subsequently,in the laboratory,the environmental stimulus on the bumpy runway during the aircraft’s ground taxi was simulated,and the operational modal parameter identification of the GARTEUR aircraft model with landing gear was studied.The conveyor belt device is designed to simulate the runway,and the unevenness of the runway is simulated by pasting aluminum sheets on the conveyor belt.The operational modal parameters of the PolyMAX method were studied,and the influence of the speed of the conveyor belt and the method of aluminum sticking on the conveyor belt on the modal identification were analyzed.Based on the ground vibration test data of the GARTEUR aircraft model equipped with a landing gear,the aircraft’s operational modal identification during taxiing was evaluated,and the feasibility and engineering value of identifying the operational modal parameters of the taxiing vibration test were discussed.Finally,the finite element model updating technology based on modal parameter sensitivity analysis is used to study the finite element model updating technology of GARTEUR aircraft model with landing gear.Aiming at the frequency correlation and mode shape correlation of the test model and the calculation model,the appropriate model parameters were selected for sensitivity analysis,and the adaptive simulated annealing algorithm was used to modify the finite element model of the GARTEUR aircraft model with landing gear under taxiing state,the frequency relative error and modal confidence criterion of the modified model meet the requirements of engineering accuracy.In order to comprehensively evaluate the quality of model updating,the same method is used to confirm the model of the GARTEUR aircraft model with landing gear in shutdown state,it is verified that the model updating method has a practical engineering application value.