Composite Fuel Tanks

[swordfish]

Hey all, i'm new here but i have used some information from this site to help me in the past (and it has allways been excellent)

I'm just starting my 3rd year doing a degree in MotorSport engineering and i have decided to take on a project of making a composite fuel tank for my Peugeot 205 because the standard one is total rubbish .

Now i'm not very clued up on composites, the only thing i have made before was a Carbon Fibre air box so i decided to do this project to further my knowlige on the subject. So to cut a long story short i'm after any information on cars that have used composite fuel tanks in the past and any literature that may have been published on the subject (it is a literary project after all)

Any help would be greatly appriciated. Thanks. Mark.

p.s. be gentle, i'm new

[qw56q]

Wouldn't composites be a bit brittle causing them to umm... shatter upon impact?

[ESPImperium]

Wouldn't composites be a bit brittle causing them to umm... shatter upon impact?

I was thinking the same thing, but i was also thinking if it was a carbon fibre-aluminium honey comb construction like they way a current chassis is made, maybes not so.

[swordfish]

Indeed, but these are the sort of problems that i have to overcome in the design process.

The alloy honeycomb mix is an idea that i toyed with as is a carbon kevlar blend for some real strength.

[qw56q]

Wouldn't composites be a bit brittle causing them to umm... shatter upon impact?

I was thinking the same thing, but i was also thinking if it was a carbon fibre-aluminium honey comb construction like they way a current chassis is made, maybes not so.

yea but


F1 tanks are deformable and wrapped in bullet proof kevlar.

[swordfish]

Aye, however the standard 205 fuel tanks are only plastic and will break in a hard impact, alloy fuel tanks will as well but it would have to be a really hard impact.

An alloy one would be the ideal budget solution (i have to fund this project myself) but theres no-way i would get away with making one as it's not interesting/original enough.

[J-Raid]

Actually Kevlar is a composiive too, as is Nomex (used in the driver overalls).

if it wasn't for price, Kevlar would be the best option for you probably.

PS. That Ferrari crash is from when (which test)? and who's the driver?

Can't recall that moment...

[ESPImperium]

That Ferarri was a especially elongated one for the driver Kroymas as he was a little overweight, and was ultimately the embarasment that led to Ferarri establishing their Clenteli department for people to buy a Ferarri F1 car but they keep it anhd maintain it.

The track was Laguna Seca.

And production methods are much changed now to back then.

[flynfrog]

I built some for another company I used to work for. They make a sealant for composite tanks used in the aerospace industry. Its not that big of a deal really think of all the new composite aircraft they all store the fuel in there composite wings.

[Richard]

That Ferarri was a especially elongated one for the driver Kroymas as he was a little overweight, and was ultimately the embarasment that led to Ferarri establishing their Clenteli department for people to buy a Ferarri F1 car but they keep it anhd maintain it.

The track was Laguna Seca.

And production methods are much changed now to back then.

http://forums.autosport.com/index.php?showtopic=72164

http://fsae.com/eve/forums/a/tpc/f/6486 ... 6510775511

[marcush.]

as for the aircraft fueltanks and racing we are talking FT-3 bladders installed into
aluminium or carbonfibre housing/trays.

with carbonfibre as the actual material ,I think something like dyneema as a fibre is more useful in terms of toughness compared to Nomex/kevlar(both are only trade names for the same material),carbon fibre or aluminium .the big concern will be first how do the fibres and resin react to the intended fuel? How do you make sure
you will have a really sealed cell and not creating a mess with fuel leaking thru less than perfect laminate .
With all those fibres you are basically heading into big time moulding processes be it Resin infusion,prepregs,etc and of course heat curing -which leeds to the need for a very good and heat resistant mould,vacuum source and all the necessary hardware and crafts...definitely not a beginners project ,sorry.
At the end you will have spent more money than buying something off the shelf ,I presume a FT3 bladder fitting into a 205is readily available also second hand...

[swordfish]

Thanks guys, as mentioned the composite tanks are used in the aircraft industry and aviation fuel has similar corrosive properties to road fuel.

I wasn't thinking about installing a bladder in to the tank i was more along the lines of a series of baffels to reduce fuel surge (what this project is all about) if i just bought a bladder (not readily available as far as i'm aware) it would defeat the object.

Any more iinformation would be appriciated, it's all been good so far.

[flynfrog]

I believe fuel safe will build a bladder to your print

[autogyro]

I would like to add something to this thread.
With ethanol being used in larger quantities in motor sport and the possibility of wide spread road vehicle use. Can some of the obviously gifted readers, please give some design ideas for keeping the surface of such liquid fuel out of contact with air to prevent water absorption?

[flynfrog]

unless the car sits for a long time its not in the tank long enough to matter. I have read some articles about ethanol fuels breaking down fuel bladders though.

If it were me I would have a second bladder that was flexible like a garbage bag then vent to the back side of it. It would be hard to have baffles though.