Originally Posted by
cycle_maven
Note the curve trend and the fact that the horizontal axis is logarithmic. At 50% stress and a hundred thousand cycles, all the metal frames have failed. The trend of the carbon fiber at 50% stress is probably failure at 10^20 or so cycles. That's an effectively infinite lifetime.
Assuming that the process used to make carbon composites don't generate any major defects that could eventually weaken the carbon nanotube structure like what is happening with graphene.
Defects and disorder in carbon nanotubes
http://www.physics.uci.edu/~collinsp...38.Collins.pdf
Though there is no info on how this graph has been made but we can assume it has been made from actual experiments.
Also the graph doesn't say what kind of test has been used. Carbon nanotubes are not as strong when under compressive, torsional stress and tend to undergo buckling.
https://en.wikipedia.org/wiki/Carbon_nanotube