A slight non-carbon related digression but the discussion of the materials properties and google led me to this: https://www.youtube.com/watch?v=Ai2HmvAXcU0

what a cool type of problem to understand and solve - I don't know if the 777 or this 777 had composite wings - but it is amazing

Composites were not widely used on the 777, but newer 777X does utilize composites in the wings. BTW, here's the 787 test - https://www.youtube.com/watch?v=sA9Kato1CxA

its amazing

how do they QC the layup of a Dreamliner body / wing? or a front wing on a F1 car to ensure that item to item its consistent?

in fact, how do they layup the body of a dreamliner? is it panels and joined? how do they impregnate resin and cure it?

I've seen footage of the VOR yachts and this is much bigger. Any ideas how its done?

its a lot of individual panels. I'm not familiar with the entire manufacturing process since I work design/analysis, but it's certainly not as complicated as you think. each part has a layup surface where a matching tool is created with the same surface. from there each layer is aligned per the drawing in a specific order (ply1-plyX), darted as required, and that's that. for thicker parts cores are used.

I hate working with composites.



nothing like stress analysis by color! and yes everything with composites is an assumption. you will see material allowable specs that have 20 correction factors for anything imaginable. in fact within the same part you have different material allowables for every area with a slightly different ply layup. it's insane.

Process control, non-destructive evaluation (checks for disbonds and voids), a proof test to a given structural load.

Panels aren't as important - you should be more worried about how the do the ribs, spars, ring frames, and longerons of the aero surfaces and body. Those are the real load carrying members. Boeing actually had issues with the wing carry through structure on the 787. Mitsubishi was responsible for some of those features, and either design or fab was causing them to fail before ultimate load. Don't recall the exact nature, but it had to be redesigned.

First, the body of the dreamliner is made up of a couple composite barrels (4 or 5 total). These are a single piece that is all laid up over a very fancy mold using a tape laying robot. This tape laying arm will apply the layers of composite at the required width/length/angle required. The reason the molds are fancy is because there are internal structures that are also layed up and cured at the same time, so mold is not a smooth surface that the barrel can slide off of, but it has negative curvature inside. Everything is inspected both visually while the robot is laying the tape and after with non-destructive methods to verify it was built correctly and that all the layers bonded correctly. Then everything is stuffed inside the barrels, the floors, electrical, hydraulics, etc and then the barrels are fastened together to create the body of the airplane. Wings are similar very large molds to make everything in large pieces and laid down by robots.

Ohh the resin is applied to the tape as it is being laid down. Then everything is sealed in a bag and put in an autoclave, where there is pressure and heat applied to the part and mold to cure the structure.

Well the real reason the 787 wing flexes is because to make a wing that would not flex would add a bunch of weight. Then once the flex was understood they built the aerodynamics around it. So there is performance from the flex, but it is not aerodynamic. In addition the wing acts a bit like a suspension to gusts, so a flexible wing can make smoother ride. It does make flight controls difficult some times.

In F1 I know they do use monte carlo analysis for their optimization. I do not know the extant or how much the even plan on the wake of other cars. Part of it is to optimize running in clean air in hopes that is where you spend the majority of your time anyway, so being fast there is good. Also in qualification you will be in clean air, so a higher grid spot at the start is worth a bunch even if you sacrifice a bit of performance following people. NASCAR on the hand does pour resources in understanding the drafting and optimizing for it.

Also, I think they changed the rules. Before they did have a silly statement like no moving aerodynamic devices. But the real rule was that you had to meet the flex tests