You'e rightthat theres a paralle between bonded carbon bikes aka OCLV, Time, et al and metal frames. The point is that the material carryingthe load has a greater yield strength in metal than in epoxy resin. S if we agree that a frame is only as strong as the joint holding it together than the metal frame will always be stronger than the bonded one
Epoxy resings and glues are only strong in shear not under impact loading, tensile or compressive loads either.
As for metals which show full recovery, youhave to look more at the heat treating processes than the metal itself. Different metals require different heat treatment to show strength recovery.
Titanium alloys 3Al/2.5V and 6Al/4V are actually stronger in the weld zone due to there being uncontaminated material there.
Heta treated AL frames like 6061-T6, 7020-T6 also show up to 95% strength recovery int he weld zone which still has a higher yield than a epoxy joint.
You onlyget the full advantage of carbon fibre composites when the frame is Mono Moulded, and I believe Kestrel is the only compnay still doing them.
As for frame life times; that may be a non issue but it all depends on how a frame is used and the strenght of the rider.
I know guys who go through 2 Easton Ultralite frames a year and train on steel which they'vehad for yrs. They also would not touch a carbon frame unless it was given to them free of charge.
we must be very care ful when comparing frmae materials. Marketers want us to believe that we are ridingthe same equipment as the Pro's. for those that can afford it, fine go for carbon. I 'm n=more discerning about my investment. If the frame does'nt give 10yrs life then it'sa no go. If I need a lightweight race bike I can get a cheap AL frame made locally, but the bike I spend themost time on is always goingt o be steel or titanium.
Al and Carbon have their uses, but they are limited in their life. It's written in the fatigue life of the material. We can't change physics.