How to repair 787 composite fus.
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Well!
There's the answer! Thanks for posting that, it all seems very well thought out and straightforward.
Here's hoping this thread is not resurrected in 2030.
I have a fair bit of experience in GRP and kevlar/ CF moulding.
If it's as simple as Boeing say it is in these pics, I'll be amazed but hey: gotta trust them!
After all, what could possibly go wrong?
Well!
There's the answer! Thanks for posting that, it all seems very well thought out and straightforward.
Here's hoping this thread is not resurrected in 2030.
I have a fair bit of experience in GRP and kevlar/ CF moulding.
If it's as simple as Boeing say it is in these pics, I'll be amazed but hey: gotta trust them!
After all, what could possibly go wrong?
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sigma 3-3
Remember sigma 3-3, that is the short transverse and I don't care how strong in-plane capabilities of composites are, you only have lousy epoxy for out-of plane sigma 3-3. There has been some nonsense spoken of this thread re toughness. so beware. Those who understand composites know this issue, but clearly a lot of pprune folks don't. The static sigma 3-3 is around 5 ksi and epoxies are lousy in fatigue, just as aluminums are, so assume at fatigue allowable of 40% of static and you end up with an tensile allowable of 2 KSI, which is close to zero. Remember the lousy recent 787 wing failure with out-of-plane loads explanations in Boeing statements. Just remember that CF layups are good in sigma 1-1 and sigma 2-2 if properly designed, but you have that dangerous sigma 3-3 matrix dominated issue at all times.
Last edited by amicus; 29th Jun 2009 at 01:50. Reason: Correction of source
