| In recent years, more and more attention has been gained to the multiaxial fatigue life of mechanical structure under complex loading conditions. In the study of multiaxial fatigue, there are relatively more influence factors and the problem is more complicated. Nowadays, most of the mechanical and engineering structures are under the multi axial stress state. With the continuous improvement of product safety requirements, the uniaxial fatigue theory has been unable to meet the needs of high-tech product life design. Multiaxial fatigue research is attracting more and more attention from researchers. Wing structure as the main force bearing components, is the main source of the lift when the aircraft is flying. The wing is subjected to various loads during take-off, flying and landing. It has important practical engineering significance to study the fatigue life of complex load.This paper firstly introduces the fatigue foundation and the research trends of multiaxial fatigue, and the theory of multiaxial fatigue life is described in detail.According to the characteristics of multiaxial fatigue of wing structure, multiaxial fatigue life analysis method based on critical plane method is considered to be suitable for fatigue life analysis of wing structure under multi axial stress state.Through the analysis of the external load characteristics of the wing structure, in order to predict the life of wing structure more accurately and fitter for the actual working condition of the wing, the combination of fluid mechanics and finite element analysis is used in the analysis. The flight external load characteristics of three kinds of working conditions are analyzed by using the fluid dynamics analysis software FLUENT. The lift force and drag force, which are the most suitable for the engineering practice, are extracted as the external load in the finite element analysis. Finite element analysis of wing structure is conducted in finite element analysis software ABAQUS.The strength and rigidity of the wing are obtained. Find the weak place on wing structure, and obtain the results of stress and strain for fatigue life analysis.In fe-safe, according to the results of finite element analysis of wing structure, the load cycle of fatigue analysis is formed under the condition of the load of each working condition. Define material properties to create new material and select multiaxial fatigue algorithm, and analyze the fatigue life of the wing structure. Through the finite element post processing, the fatigue life and the weak position of fatigue on the wing structure are obtained. It is concluded that the maximum stress is consistent with the weakposition of fatigue via the comparison of the results, and the minimum cycle time of the wing structure is in the range of reasonable landing times. Comparing the fatigue life and engineering practice, it is known that the method used in this paper can effectively predict the fatigue life of the wing structure. It provides a new approach for fatigue analysis of wing structure and reference for the estimation of design service life of wing. |
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