| The majority of investigation in the field of structural fatigue has been mainly connected with the estimation of fatigue life since the fatigue failure is the main failure modes of aircraft structure which is under alternating load condition. Because fatigue life is affected by many factors, and the phenomenon of the fatigue mechanism is very sophisticated. Therefore, it's a very important theoretical and engineering significance that the structure of the fatigue life and fatigue reliability would be calculated correctly and effectively.At first, the research achievements of the structural reliability analysis of fatigue strength by the scholar home and abroad has been reviewed, researches on structural fatigue reliability of the stress-strength interference model has been described, and on this basis, the calculation of structural reliability and fatigue reliability analysis method of the structural elements at home and abroad has been discussed as well. It is considered that the stress and strength are subject to certain statistical distribution of random variables by this structural model. That structural strength is greater than the probability of the structural stress can be called structural reliability. It is the basic model of the application in structural reliability analysis, being widely used in the calculation of various types of structural reliability.In this paper, the fatigue load suffered by the aircraft is analyzed by using appropriate statistical data. The rain-flow counting method——a treatment changing the load-time histories into a complete cyclic loading has been described. At the same time, the generation of aircraft load spectrum has also been illustrated. The load size and frequency on the wings of the aircraft in the different environment has been calculated through appropriate statistical data. According to the fatigue life curve, the fatigue life of the wings should be calculated through the nominal stress method and cumulative fatigue damage theory.Finally, the forces of the aerofoil has been analyzed, and the model of aerofoil has been simplified, through using the last data the strength of the aerofoil has been computed, by using the stress-strength interference model, the reliability of the stress and strength when they are subject to the normal distribution has been analyzed. At the same time, the reliability of wings under the action of the gusts has been studied theoretically. In the actual structure, when the average of stress intensity is greater than the average of stress, the reliability of the structure is more than 0.5. When the differences of the both are the fixed value, The larger the variance of the stress and intensity is, the greater the probability of structural failure should be. |
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