The Key Technology Research Of Wing Flutter Modal Analysis

The three important factors that affect the flight safety of the aircraft are the aircraft stall,the engine off in flight and the flutter of the aerofoil.One of the most important problems in the related field is how to make full use of the measurement of the flutter airworthiness in the flight data envelope.The wing dynamic deformation and flutter characteristics are not only the important factors affecting the performance and safety of the aircraft,but also one of the key test contents of the aeroelastic deformation analysis,flight test subjects and flutter airworthiness certification.Therefore,it is necessary to obtain as many wing deformation and flutter measurement datas as possible,so as to provide sufficient test datas for aircraft structure design,airworthiness certification test and application,which could ensure aircraft performance and flight safety.It is vital to determine the positions of test points in the Wing flutter airworthiness test.While to some extent,the weak parts of stiffness or intensity of the structure could be mapped by the stress,strain and deformation displacement of the modal response or other dynamic responses of structure,which would be treated as the significant flutter airworthiness test positions usually.The purpose of the subject “the Key Technology Research of Wing Flutter Modal Analysis” is to simulate the wing flutter modes under different conditions through the finite element simulation,then the weakness region of the stiffness or intensity of the wing structure would be determined,which could be reference for the selection of wing flutter airworthiness excitation test points as well as the design of aircraft.1.The mathematical model of the NACA0012 wing is established firstly,and then the flutter modal response and transient dynamics response of NACA0012 aerofoil,which is treated as the universal airfoil,are analyzed.Then the finite element analysis is verified to be reliable and correct by the comparison with in response to the theoretical values of natural frequency and transient steady state displacement response.And the influence of fluid on wing flutter modal response is analyzed by contrasting in modal response under the coupling flow conditions.Finally weak parts of the stiffness or intensity of the wing are obtained.2.In order to ensure the selection of flutter excitation region is closer to the actual,the modes and other vibration characteristics are analyzed based on Ansys Workbench,which choose the Boeing737-800 wing as the research object,and the concentration distribution zone of deformation displacement,stress as well as strain of the wing is obtained finally with comparison with various dynamics results based on MSC.Nastran.3.In order to ensure the effectiveness of the simulation of the subject,the simulation results of the flutter test are contrasted to the selected measurement position of wing and experimental results in aircraft flutter airworthiness test of Langley Research Center,and the conclusion could be same basically.