Simulation Research On Fixed-wing Aircraft Flight Dynamics And Vibration Characteristics

With distinct structural features,fixed-wing aircraft could achieve more functions and its application areas are extremely broad in many aircraft, so the aircraft flight characteristics as well as the safety and efficacy when used are important. In this paper,aircraft flight dynamics and vibration characteristics are studied from the modeling and simulation analysis under the background of a light fixed-wing aircraft.In order to ensure accuracy and reduce the complexity of the model, the aircraft is considered as the 6dof rigid body which is plane-symmetry and variable-mass in establishing dynamics model; Atmospheric and mechanical environment of the aircraft are analyzed,aerodynamic parameters are calculated, an aerodynamic data approach is given; Dynamics model is solved by using standard four-order Runge-Kutta and the Matlab program is applied to perform the aircraft dynamics simulation; For preset flight path, main flight dynamics parameters are selected to compare and analysis the simulation results and the flight-test data,comparison results show that the simulation reflect the actual flight conditions and dynamics characteristics properly, verify the correctness and effectiveness of the modeling and simulation methods.In establishing finite element model, the aircraft structure is simplified and divided into fuselage, wings and tail, which based on the structural characteristics and bearer analysis, and then the whole structural finite element model is established in ANSYS. Based on the model,Block Lanczos method is chosen to calculate aircraft mode,full method is used to calculate the axial, longitudinal and lateral vibration displacement changing situation in key position over time in various dynamic loads. The calculation results show that heading and attitude change will lead to more intense vibration,the vibration generated after a single excitation is always in the attenuation state; axial and longitudinal direction of the aircraft is the main response to dynamic load,in the axial and longitudinal direction,the vibration amplitude is relatively large and the frequency is higher. Simulation results verify the validity of the modeling method and reflect the aircraft vibration characteristics.