Small Uav Airframe Life Analysis

In recent years the UAV (Unmanned Aerial Vehicle) has been wildly used in military field and civil field. The life of the UAV becomes more and more important. But no one is engaged in the research of the UAV structure life currently. This paper studies the method of small UAV structure life prediction under the background of needing to estimate the life of a small UAV structure.This paper introduced the fatigue life prediction method of aircraft structure. The character of small UAV structure is analyzed from the materials, the design load and the load character. An analysis of the usage of the small UAV has been given out.Bases on the aircraft structure fatigue life theory, consider the characteristics of small UAV, the model of fatigue life prediction for small UVA structure is established. Firstly, the method of drawing up load spectrum is introduced briefly. Secondly, this paper discusses the theoretical basis of methods that are usually used for metal structure fatigue crack-forming life estimation, i.e. the nominal stress approach (the stress severity approach), the local stress-strain approach, detail fatigue rating approach (DFR). Also the processes of life estimation of these approaches are studied in the paper. Thirdly, from the residual strength, residual stiffness, residual fatigue module and the fatigue damage cumulative rules of the fatigue life prediction, the fatigue life prediction method of composite laminate structure is conclude to estimate the life of composite structure of small UAV. Finally, depend on the methods of fatigue life prediction; we computed the life of the typical components to estimate the life of small UAV structure.Through the analysis of typical components life above, this paper provides a reference to improving the estimating and prolonging the fatigue life of small UAV.