Abstract
The service life of aircraft structural components undergoing random stress cycling was analyzed by the application of fracture mechanics. The initial crack sizes at the critical stress points for the fatigue crack growth analysis were established through proof load tests. The fatigue crack growth rates for random stress cycles were calculated using the half-cycle method. A new equation was developed for calculating the number of remaining flights for the structural components. The number of remaining flights predicted by the new equation is much lower than that predicted by the conventional equation.
This report describes the application of fracture mechanics and the half-cycle method to calculate the number of remaining flights for aircraft structural components.
Résumé
On a analysé en application de la mécanique de rupture la vie en service de composants de structures aéronautiques soumis à une sollicitation cyclique aléatoire. A l'aide d'essais à la charge d'épreuve, on a établi les dimensions initiales d'une fissure aux points critiques de sollicitation, pour analyser sa croissance par fatigue.
Les vitesses de croissance d'une fissure de fatigue dans le cas des charges aléatoires ont été calculées par la méthode des demi-cycles. On a mis au point une nouvelle expression pour calculer le nombre d'heures de vol résiduelles pour des éléments de structure. S'il résulte de cette nouvelle expression, ce nombre est beaucoup plus faible que celui prédit par les équations de vie résiduelle conventionnelles.
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Ko, W.L. Application of fracture mechanics and half-cycle theory to the prediction of fatigue life of aerospace structural components. Int J Fract 39, 45–62 (1989). https://doi.org/10.1007/BF00047439
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DOI: https://doi.org/10.1007/BF00047439