NASGRO High Humidity Air (HHA) for Material Crack Growth Properties
NASGRO High Humidity Air (HHA) for Material Crack Growth Properties
(OP)
I guess the crux of my question is "are all high humidity air environments equal" or, at least in terms of NASGRO database HHA, is the definition of HHA sufficient to cover civil aircraft without a further environmental knockdown factor? Assume of course the affected area of analysis does not involve sump, fuel, saltwater, etc. environments.





RE: NASGRO High Humidity Air (HHA) for Material Crack Growth Properties
How do you validate the real world environment relative to the specified laboratory environment for crack growth curves, particularly NASGRO database material data?
RE: NASGRO High Humidity Air (HHA) for Material Crack Growth Properties
Early in my career I queried my then-employer about the fact that we did not take into account the (approx) +20C to -40C to +20C thermal cycle that external structural components, like wing skins, would experience. I never really got much of an explanation and did not pursue it. In any case, it can be argued that this thermal cycle is of little significance.
Short answer: No knockdown factor.