Computing the growth of small cracks in the assist round robin helicopter challenge

Rhys Jones, Daren Peng, R. K.Singh Raman, Pu Huang

Research output: Contribution to journalArticleResearchpeer-review

10 Citations (Scopus)


Sustainment issues associated with military helicopters have drawn attention to the growth of small cracks under a helicopter flight load spectrum. One particular issue is how to simplify (reduce) a measured spectrum to reduce the time and complexity of full-scale helicopter fatigue tests. Given the costs and the time scales associated with performing tests, a means of computationally assessing the effect of a reduced spectrum is desirable. Unfortunately, whilst there have been a number of studies into how to perform a damage tolerant assessment of helicopter structural parts there is currently no equivalent study into how to perform the durability analysis needed to determine the economic life of a helicopter component. To this end, the present paper describes a computational study into small crack growth in AA7075-T7351 under several (reduced) helicopter flight load spectra. This study reveals that the Hartman-Schijve (HS) variant of the NASGRO crack growth equation can reasonably accurately compute the growth of small naturally occurring cracks in AA7075-T7351 under several simplified variants of a measured Black Hawk flight load spectra.

Original languageEnglish
Article number944
Number of pages16
Issue number7
Publication statusPublished - Jul 2020


  • FALSTAFF flight load spectra
  • Fatigue crack growth
  • Helicopter flight load spectra
  • Small cracks

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