So I'm working on an AA degree in composite's and have to fab up something. I'm limited to what I can make (e.g No hoods) and I was thinking about making Carbon fiber / fiber glass 8 ply composite armor. My question is, Has anyone done something like this? I dont thinking it will be as strong as steal unless I use a honey comb core(which I may end up doing). I will post pictures as I get further in the project. Has anyone got a 2nd idea I could use to make something for my 97 cherokee?

 

man i work with composites everyday. from a functional stand point, i have seen honeycomb crack under pressure applied with someone's finger, i would also think that you would want to incorporate some kevlar plies in the stack up somewhere, being that kevlar is great against impacts. also, 8 plies is not nearly enough....each ply s/b ~.007 thick
what kind of tooling (layup mandrel/form die) are you using? what kind of cure cycle and resin? man i got alot of questions....this would be a really fun project. keep us posted, with pics if possible.

joe

 

Yah I scratched the honey comb core idea, Our lab has this plastic / foam core I can use that is much more beefier. I thought about using kevlar as well. And I was going to use PrePeg 350 degree carbon fiber. As for the tool, well I hadn't thought that up yet. I wanted to see what the curvature of the quarter panel is and go from there.

 

Oh, and I didn't expect this armor to be as strong as steel, I just wanted something different and to test out ideas to see if I could get something going.

 

Id make a visor for your windshield or something else along those lines.

 

Make a carbon fiber hatch!!!!! That would be something I would buy.

 

I wonder if something floor pans might be a good idea. Not sure how much they get hit if wheeling, but floor pans appear to rust out often and would be a neat to offer a light weight replacement alternative....and races (if there is any left that use Cherokees) would buy jst for weight savings. Of course this is just for a school project...so bottomline...finish it on time, and KISS.

 

Kiss = keep it simple stupid

Someone was bound to ask.

 

The hardest part about using composites is making a tool(mold). I can make just about anything buy our oven to cook the part isn't very big(about the size of a conventional oven). I'm going to experiment with this quarter panel armor. If all goes well I will try making door armor too.

 

Taillight housings to hold led lights, Bingo!!!

 

Supply me with the carbon fiber PrePreg and I will do it ( 2 yards = $120 @ Pacific Coast Composites Lakewood,WA)

 

x2 on taillight housings or fender flares.

 

Thought about fender flares as well, But the armor is pretty close to flat which will be easier in the end to make. I will have future projects I will need to design and build and I wouldn't mind helping someone out here that I know and would use / appreciate what ever I make for them.

 

I have a spare set of taillights if you need the dimensions or whatever for a mold and I would sport a set of CF light boxes if you make some that dont cost $100000000.That little tile you made out of scraps was tough as hell and we just need a rectangle for light boxes Text me if you want to try it out.

 

my job is to design composite tooling for a major aerospace co in the puget sound area. its alot of fun and i really enjoy it.
ideally if you were to machine a layup mandrel, and you were going to use prepreg with a 350 degree autoclave cure, you would want to use a super high nickle steel alloy so that the CTE would be similar.
something like quarter panel armor would be a simple LM compared to something like floor pans because of the contours . also, if these parts were to ever be functional, you would need to use a resin compound that doesnt absorb moisture, otherwise it wouldnt last very long.
there are some foam materials out there that have pretty good CTE attributes, that i have used for LM's, they wouldnt match the CTE of the prepreg but they would get the job done.
yes prepreg is very expensive, but it is worth it. we are doing some pretty amazing things at work with numerous different types of composites. the possibilities are endless.