Dynamic Analysis And Optimization Of Landing Gear Connector Of Multi-rotor UAV

With the development of science and technology, multi-rotor UAV is already widely used in military and civilian fields. It has received more and more attention from researchers and has made considerable achievements. During the flying of Multi-rotor UAV in the air, there would be vibrations due to vibration sources such as the presence of motor and the wind. The vibration of multi-rotor UAV will affect the normal flight of UAV, resulting in vibration sensor and decreased the working precision of sensor. In serious cases, if the resonance happened, the structure of the UAV will be destroyed.To solve the problem of vibration, we must investigate the dynamic vibration characteristics of multi-rotor UAV in first. This article subject to multi-rotor UAV what research group studded for the study, based finite element modal analysis and transfer path analysis, this paper determined the dynamic characteristics of multi-rotor UAV, and in accordance with FEM topology optimization, this paper multi-rotor UAV optimized accordingly.We established the 3D model of multi-rotor UAV in UG according to the existing multi-rotor UAV, and confirmed the simulation scheme; We also made a series of simplification of the UAV, such as ignored the non-load bearing member and the small size holes, properly simplified complex shaped parts, rounded and smooth handled. After exported the simplified model to Patran and Ansys, we established the finite element analysis model of multi-rotor UAV.After free modal analysis of the UAV models by ignoring the structural damping, we got the first 12 order modal information, and a transient response analysis of UAV also has been taken, and we got the response surround the sensors. Through the vibration test of sensors, we detected the results and simulation results and obtained in the Z direction of vibration greater, that results proved the correctness of the simulation results.A vibration transfer path analysis of the multi-rotor UAV has been taken in using CAE and vibration transfer path method; we obtained the vibration transfer function after frequency response analysis of the UAV, through the inverse matrix method, we got the work load of the UAV, and we determined the main transmission path of the vibration.Established the finite element model of the UAV landing gear connector, after topology optimization, we obtained the information of the material which can be removed; modified the landing gear connector model according to the results of topology optimization, after static strength analysis of the modified model, we obtained a good optimization results.In this paper, we got the modal information and other dynamic characteristics of multi-rotor UAV through simulation and testing, and we also obtained information and the main transmission path of vibration around the sensors which can provide a theoretical foundation of vibration attenuation. Finally, a topology optimization has been implemented, and we obtained the optimized landing gear connector.