Man made silk composite - impressive stuff. I guess diamond fibre composite is the next step. Carbon fibres (Bucky tubes) may hold the secret to room temp superconductivity too...
I was looking at some Goodman diagrams of composite, and was suprised that the numbers didn't look that different to high tensile steels above fatigue limit stress (but density is obviously much lower). Do you have a preference for type of carbon composite? I gather that kevlar is intermixed with CRP in the EH-101 airframe, due to it's improved fatigue characteristics - moisture absorption would not be such a concern here. Using compressed resin to introduce fibre tensile loads will help to push up fatigue life too.
I am a great fan of wood, but was amazed to hear how little of (say) a spruce tree you can use. You can only use the trunk from above ground to below the first branch! I imagine that compreg is only one type of wood composite available to overcome this hurdle.
Interesting to learn how F1 uses photo stress to optimise layup too. The bonded platic layer for measuring strain (using polarised light) is marked up with isocline contours, to determine strain (or stress) gradients for particular load inputs. This helps perfect the fibre orientation after CAD/FEA first pass.
BTW Slowrotor, i would seriously steer you clear of welded fabrications for rotor blade assys. Although high tensile steel may be good for 200MPa fatigue max principle stress (metric - don't understand "English" units
), the weld is at best 100MPa - conservative estimates state 30MPa! Worse is that welding introduces preloads, and stress concs that result in local tearing. This is the main reason aero went off towards riveted ally, while auto developed spot welded steel...
Mart