Analysis of Fatigue Crack Growth under Random Load Sequences Derived from Military In-flight Load Data
Résumé
The crack growth process of a crack initiating at a hole of a skin-stringer panel in a fighter aircraft subjected to random variable amplitude loading is investigated in this paper. The generation of synthetic random load sequences hinges on Markovian models for which their parameters are identified from real in-service recorded flights, which gives these models a real sound basis. The ability of these stochastic models to capture and recreate the load scatter measured on a French fighter aircraft fleet is first appraised. The most efficient model serves then to probabilistic crack growth analyses under random loading. It is found that the extreme load values as well as the length of load sequence being repeated through the load spectra must be considered as driving parameters for crack growth analyses under repeated load sequences.