Posted on 06/12/2007 6:48:29 AM PDT by Freeport
When Boeing first considered extensive use of structural composites on the 787 Dreamliner, its engineers knew intuitively the epoxy/carbon fiber matrices would reduce weight significantly, allowing fuel savings and extended flying range. But after an intensive early look at composites, they realized fundamental design changes were possible that would allow functional systems integration, as well as changes in lamellar flow that would improve aerodynamics From a materials point of view, the 787 Dreamliner is one of the most revolutionary leaps in the history of manufacturing.
But in order to meet an ambitious delivery schedule the first delivery is scheduled for May 2008 there were tremendous hurdles to jump:
- No one ever attempted to mass produce very large carbon-reinforced plastic structures, which are thermoset materials with significantly slower processing times than thermoplastics,
- The critical tooling for such large sections was still very much in the development stage and, in fact, represented one of the few, small stumbles in the development program,
- New coatings had to be developed to deal with the crack propagation issues, which are not a factor with aluminum. Engineers had to devise different systems to deal with electrical shorts because composites are not electrically conductive.
One area that was not new was the materials technology. When we made the decision on composites use in the wings, fuselage, floor beams and so on, we went down a path based on a material that we had already had a significant amount of production experience with on the Triple 7, says Dr. Alan G. Miller, director of technology integration on the 787 and former chief engineer for all materials technology at Boeing...
(Excerpt) Read more at designnews.com ...
Well, less than 5’10 I am, but I’m well over 110 pounds! I find that if someone is next to me, that my entire lower region is sore, cramped, and uncomfortable for hours after flying.
OOOooooooohhhhh, you must be a very discrete and yet remarkable person to be able to perform like that for hours on a plane..... ;-)
Um...not for that reason. More because my legs are smashed together diagonally and my manhood flattened between them for hours.
Something else I came across is that the 787 will have a gust compensation system for the vertical and horizontal planes. The 777 only has one for the horizontal plane. That should make for a very smooth ride.
I thought it was only a couple, can you point me to information showing "several" A380's flying?
I did see a photo of a 3 ship formation.
Google "A380 production list" for those that are flying, A380 photos" for the pics.
Clearly a triumph of European Engineering and Ingenuity.
Viva La France and all that.
Not a problem. Although carbon is a bit harder to work with than fiberglass, it isn't hard to repair at all. As a material, it's harder to work with, mostly because it's hard on tools such as drills and cutting implements. It also conducts, so static can be an issue.
One problem with carbon is when it is bent to the point of failure, it very often fails almost explosively. If, for incidence, you take a carbon tube, such as a windsurfer mast, and bend it to the point of breaking, it doesn't just snap like a twig. It explodes and delaminates. The result is very often not repairable. OTOH, if you punch a hole in a carbon sheet, such as a wing section or fuselage side, it's easy to repair.
Thanks - I own a tool and die shop so fixing metal I know all about, but I have never worked with carbon fiber before.
Not all composites are nonconductive. Carbon is conductive.
Not sure about what Boeing is doing with the 787, but embedding conductive wire mesh is in the structual laminate to dissapate static charge is common practice in several composite homebuilts I'm aware of. Most notably, the Lancair, has been using this technique for about 10 years after some rather catastrophic failures after lighting strikes in flight.
No problem. Although I'm an electrical engineer by trade, my partner and I do composite sailplane repair and refinish nowadays. I also built a composite Europa XS touring plane, completed last year. I don't have the mesh in my Europa and I'm very careful about flying near convective weather.
Composites, and in particular epoxy/carbon or epoxy/fiberglass, are great materials to work with.
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