Mechanics Characteristic Analysis Of Drive System Of Heavy-duty Four-rotor Unmanned Aerial Vehicle

Multi-Rotor Unnamed Aerial Vehicle(UAV)is a newly developed aircraft in recent years.Its structure is relatively simple,but its function is powerful and flexible.It has very broad application prospects in agriculture,military,fire protection,commerce and other fields.Fueldriven UAVs require a transmission system to transfer engine power to four propellers.Based on the modern design method,the purpose of this paper is to analyze and optimize the mechanical characteristics of the drive system of the new fuel-driven UAV.In this paper,the structure and working principle of a new fuel-driven UAV transmission system are introduced in detail.Starting from the mechanical analysis of new composite structure materials and the structural mechanics analysis of assembly,the failure criteria of CFRP structures are explored,including the mechanical properties of composite materials,the relationship between the mechanical properties of composite materials and the angle of lamination.Using 3-dimensional drawing software such as CATIA and UG to design and model the structure of composite transmission shaft,the structure of intermediate shaft containing composite transmission shaft,the test bench of external shaft of support arm and the coupling of internal shaft of support arm,ANSYS software is used to analyze the finite element strength of the transmission system containing the above-mentioned carbon fiber test pieces.The tension test of the arm outer axle was carried out,and the arm tension test bench was designed and manufactured.The strain and displacement of the arm outer axle of UAV under the propeller ultimate lift load were verified by the limited load,the ultimate load and the failure load,respectively.In the test part,the torsional strength of the carbon fiber transmission shaft is tested.By taking a section of carbon fiber tube for torsional test,the relationship between torsional angle and torsional moment is observed,and the weak torsional position of the carbon fiber transmission shaft is found out.The torsional strength of carbon fiber transmission shaft was optimized by calculating the bonding parameters and the mechanical connection hole position parameters based on the principle of carbon fiber composite hybrid connection.The analysis and test results show that reasonable connection mode can effectively improve the connection strength between carbon fibers and metal components.Using CAD/CAE technology,and the design level of the drive system of the fuel-drive UAV is improved,the design and verification cycle is shortened,the cost of research and development is reduced,and the light weight direction of the UAV has obvious advantages.