I have seen charts and data, but they are dealing with the full sized aircraft. I don't think that data deals with scale applications. As hobbyist we are dealing with unknowns. Unfortunately the military benefits from our experiences in terms of drones and UAVs but we do not share the same luxury.
ORIGINAL: Woketman
The time frame is determined by load, cycles, temperature, cycles, etc. Any skin, be it metallic, or composite, or a combo has to be analysed, based on test data, as to its fracture properties to determine life.