dzolcali said:
Also, heres a quick bit of info, carbon fiber is not used on planes...why you ask? Because planes get struck by lightening very often, it cascades over the capsule...however if the plane were made of carbonfiber and were stuck...lol goodbye plane and passengers. dun dun dun...NOW YOU KNOW!
Your an idiot. Thats why the F-22 is mostly composite right? Oh and I suppose you know about the plane Boeing is starting to built that is entirly composite as well. There's that other little plane company, um I think called Airbus?, that building one as well.
XJ Un-Limited said:
I beg to differ on the CF not being used on airplanes, or any aircraft for that matter for structural use. The entire aircraft isn't made of the stuff, it's way too brittle, but sections and panels are, such as tails, doors, and non-load bearing frames.
See above, planes already use C.F. rudder assemblies. While yes it is brittle in the sence that fiber break or shear, the point at when the shear should be thought about. 300m will fail around 260-280 ksi maybe 300ksi. Carbon will fail at about 620ksi, and depending on the setup can have even higher strengths. So yes it will have a brittle failure but the point at which it fails, steel would have said bye-bye much earlier.
The problem with carbon is it's depenant on layers, which are usually uniform and contain air bubbles, gaps, ect. The cross section are not nearly as nice as steel is. You have problems with internaly cracks froming in these gaps, usually the fiber will stop the crakc from spreading but it still could cause a failure point. Another problem is external abrasion that would crack or break fibers. Since the fibers are what carry the load and breaks will reduce the amount that fiber can carry and possible weaken the structure. There are ways around this problem though. Another problem is direction of the fibers. Composites are usually the strongest in tension, not compression or bending (Kevlar and Boron are better in compression). This means multiple layers need to be run so there are always fibers in tension, carrying the load. Froming composites is fun to say the least. Layup and molds take tons of time and material is hard to get and expensive. Most of the stuff built is overbuild cause of the uncertainties, increasing the weight and cost. Resign also adds to the weight as most parts need to be about 30-40% fraction of volume but end up higher at 50-60 due to layup proccess.
From an engineering stand point composites are a completly new field and analyis of them is difficult to say the least. You can't treat the compounent as a solid piece like steel because we don't really have a good idea how stress travel between layers or how they effect the stress and strain. Finite is the only way to analyize a composite parts and even then it's a mess.
Carbon on Jeep parts? Sure why not. It could be done but several things need to kept in mind. Rock damage and scars could be dealt with creativly. I know a little about composites but really not all that much overall, just stuff I've picked up here and there form a few parts I have helped make and listening to others, plus a few classes.
Actually no one is really an expert on the stuff even the guys at Boeing are finding out new things all the time, so I'm not really sure anyone here should be running their mouth as the formost expert on the stuff.
