Design And Strength Analysis Of A Civil Heavy-duty Quadrotor UAV

Quadrotor UAV(Unmanned Aerial Vehicle)is a new type of vertical takeoff and landing aircraft.It has broad application prospects in military and civil fields.Quadrotor has the advantages of wide application,simple mechanism,high reliability,high maneuver performance and low cost.The conceptual design,structure design and finite element modeling of a heavy-duty quadrotor UAV are carried out.The strength,deformation and stability analysis is achieved based on finite element method.The layers of the laminate structure of the UAV are optimized.The basic structure configuration and flight principle of the quadrotor UAV are introduced.The performance parameters and structure layout of the quadrotor UAV are determined based on design requirements.The power unit design is completed according to the performance parameters.The configuration scheme of the electrical motor and electronic currency regulator are determined by calculation.The three-dimensional geometry models of center plate,arm and landing gear are established.A folding arm connector with lock mechanism is designed which has simple structure and easy operation characteristics.Folding connectors can reduce the size of the UAV in packed configuration.The digital model of the UAV fuselage structure is assembled virtually,and the assembly relationship between the components is clarified.The finite element model of the arms and central plates is established in which CFRP(Carbon Fiber Reinforced Plastic)material is used.Numerical simulation of the arm and the central plate is carried out.The strength,deformation and stability analysis of the arm and central plate is accomplished and confirmed.The layer structures of the arm and the central plate are optimized according to the results of finite element analysis.Not only the design requirements are met by the optimized arm and central plate,but also the lowest weight is achieved.The weight of every single arm drops by 90 g.The weight of four arms decreases by 360 g,about 43% lighter compared with initial arm structure.The weight of central plate drops 203 g,about 35% lighter compared with initial central plate structure.Weight about 563 g is saved by the whole fuselage structure optimization.The revised finite element model is proved to be reliable according to the comparison between the static test andanalysis results.The flight control system of civil heavy-duty quadrotor UAV is built.The manufacture process of the UAV structure parts are studied according to design requirements.All the structure components are completed and regulated.The manual lay-up process of carbon fiber laminate with vacuum bag at normal temperature is introduced.The manufacture process of tube with square cross-section is explored and improved,and a new process with high quality,easy mold unloading and low cost is given.