DB1 Side Impact

The proper combination of composite materials, located and laid-up properly can be as strong if not stronger than aluminum in this application. It is true that composites can't substiute metals in certain applications but this application is favorable to aramid(Kevlar)/glass. The antiballistic protection used by the military is constructed with many layers of glass and/or aramid. Would you end up with heavier body work? Perhaps. If you go adding alu. sheets and steel bars you will definately add much more weight for the similar amount of protection.

MY .02 (obviously)

SEM

Steve,
Thats' true. I just thought that If I need something to contain a bead seat, it might as well serve another purpose.

An interesting product... Just happened to see it on TV yesterday:

http://www.alulight-america.com/lwsmain.htm

So, what I would like to know is that if you are going to put down 3 layers of kevlar, should each layer be cured individually, or should the whole job be done in one shot? If using the home-made pre-preg method, this would seem fairly simple.

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Originally Posted by preform resources

The use of peel ply is to enhance secondary bonding,however if you are reinforcing an existing substrate you would have no need for peel ply as the surface is already established so you would put your new kevlar/carbon etc. on over the old surface that why the surface must be free of paint ,roughed up with sandpaper and cleaned with solvent before laminating then do all your lams at once. Peel ply is used between layers when you debulk the initial layers of reinforcement and subsequent layers /cores would be applied in a seperate operation or if you were bonding anothe piece of structure /brackets etc.secondarily.
Dave Craddock

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I thought that DB1 (my old car) had kevlar in the side panels but since my grandpa started calling me senile when I was 5 years old, I was second guessing my memory.

Tom, you are the king! (king Tom - nice ring to it) ;) ;)

Quote:

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Originally Posted by Stan

..... FVs had exposed pointy ends and tube frame front and rear structures for more than 40 years before I joined the CRB; Formula Fords for over 35 years, and F500s for at least 20 years. So please don't try to pin this on me. Stan

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Geez, Stan. Learn to read! Nothing in my post stated any such thing!

The rest of your post is pure delusion as to what really happened to get the rules reinstated, and not worthy of comment any further...


To everyone else:

We've posted many times that we feel that 2 layers of Kevalr is nowhere near enough, based on a direct comparison to aluminium in both thickness and tensile strength. Our basis for that opinion is that encapsulating the kevlar fibers in hardened resin has to substantially decrease the ballistic cloth characteristics of the material and make it behave more like any other solid material (someone who actually knows the changes, feel free to correct me if I'm way off the mark!) 2 layers of the required kevlar is more likely equivalent to about .020 or so of aluminium if this theory is correct. We've also seen way too many incidents where something has seemingly easily penetrated these kevlar panels when they probably should not have done so.

If this is all correct, the minimum number of layers should be increased to either 5 or 6 to get the performance closer to that of .060" of aluminium, and even more if your wallet and minimum weight can stand it. Champ Car and the IRL both require a minimum of something like .125" thick material in one layer, and this year the IRL is adding a thick layer of Zylon (??? - the same fiber being used for the wheel tethers, I believe) to the sides of all tubs. Granted, those cars get hit a heck of a lot harder than we ever will, but you can see where the rest of the industry is heading.

The new Citation FB will have a rear attenuator that will also be adaptable for use on regular gearboxes.

Richard,
You are correct. I agree that the layers of kevlar need to be increased in the rules. In my first post on this topic I suggested 3 layers in addition to the glass. I also recommended vacuum baging to keep the resin content low as, you are also correct, the resin greatly diminishes the kevlar's anti-intrusion capability. There are certainly enough shops around that can do this type of work and it really wouldn't be that expensive versus adding steel bars and sheet alu.

Mr. Wilson,
I agree that that is a good dual use! Go for it and please let us all know how it works out.

NA94,
You can add all three layers at once. There is no need to cure each layer out before adding the next. Make sure to use only enough resin as is necessary to wet out the kevlar completely. Once you get a layer laid down blot the hell out of it with paper towels and then add the next layer. Now, That is for the do-it-yourselfer. Vacuum bagging will produce far better results and will therefore be stronger/safer.

SEM

I like it! Does anyone have any plans showing how I can convert my wife's oven and vacuum cleaner into an autoclave?

Larry Oliver
International Racing Products

Quote:

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Originally Posted by Larry

I like it! Does anyone have any plans showing how I can convert my wife's oven and vacuum cleaner into an autoclave?

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Step 1: Send your wife to the mall for the afternoon. :)

I am going to comment again to the people who are discussing rules in certain clubs.
I am glad to see some discussion of this issue for rules to protect others in the future from this type of incident, thats a good thing.
I can say w/o a shadow of a doubt(in this instance) kevlar wasnt enough protection.
I now know my car did in fact have the kevlar, and had it installed correctly to the current (SCCA rules in this case).
it was like it wasnt even there. if you guys are talking about more kevlar as the fix, then your issuing a placebo. In my region there are no cars running in this class in SCCA(less than 2), so i dont run with that club in this car. i also see low car counts in the other scca region close to me, so i am not going to be governed by a clubs rules to make the changes in safety that i see are VERY nessecary in this car for this type of incident.

The Bald Spot bead seat has been ordered, much better than foam. the foam took a big hit, and likely saved me from much worse, but there is a better product out there, and i am going to use it for the next time, as there will be a next time if i keep racing.

I am also going to use the aluminum as a bucket for the bead seat to sit in, sounds like a good idea, and an extra layer of protection.
I am also going to see what kind of bars can be welded into the cockpit near my hip area. should not be too hard to have done, and imo will go a long way to prevent intrusion.
some sheets of aluminum are also going to be looked into as a lining inside the car.
if all this makes me weigh 15 lbs more, than so be it, I likely already weigh more than most others in the DB-1, i am 6 feet, and 195 lbs. i fit into the car snugly, and i dont see myself underpowered in the group i run with. i am able to run upfront with all the cars, and most of the drivers are lighter than i am.
You can mandate all the kevlar you want, but your just not really solving much more than giving the appearance of safety, and issuing a placebo.
I know as I was really lucky to be able to walk away, and just have some broken ribs. an inch lower, and my hip would have been crushed, a few inches higher, and my ribs would have been in bad shape(worse than they are).
I am not trying to be mean, but just trying to be a bit more assertive in what i saw with my car in this case, and see when i look in the mirror at my side of my body.

yes the kevlar likely helped, but no way would i just put more of it on the car and proclaim the issue is resolved.
i am glad that attention is being brought to the issue for others. i would hate to see anyone seriously hurt in an impact like this.
the reason for me posting here is to help others be safer, thats all.
Josh

All the best seats I've see have sides. The lap belts come thru a hole in the sides. In order to support the bead seat sides it should rest against secured metal panels. In this case the panels serve 3 purposes,

1. Support seat making it last longer
2. Inrease surface area for seat/driver to crush against (Better then round tubing)
3. Intrusion support of vitial organs

To me, having these panels in this area are worth the mininimial extra weight.

Josh,
Your incident has probably gotten a lot of us thinking about our own safety precautions. I know I'm thinking about some potential changes to my FF, even though I think your incident was a really rare one. Of course, they're called "accidents" because we have no way to predict them and our only recourse is to learn from the experience of others - thank goodness for this site!

BTW, if you add a bunch of panels, just get an alum head and you'll loose all or most of the added weight!

Josh:

Contrary to what you seem to be thinking, adding a few extra layers of kevlar will indeed help, but that is not to be confused with it being a cure-all, as there is no such thing.

As with any minimum safety standards, they are there only as a basic guideline, and you are free to build to any higher standard that you may wish - as long as what you do doesn't run afoul of some other rule set.

For instance: You could easily add welded steel panels all along the sides of the car, but would have to figure out a way to make them pass the stressed panel rule (yes, it can be done).

Also, just because the rules do not yet mandate rear attenuators, you can still use them, and are actually highly encouraged to do so. At some point the Club will see fit to make them mandatory, but we haven't been able to get them there as yet.

The clubs that require rear "shift guards" for FV and push bars for FF's, etc, could easily come up with "standard" designs that incorporate the vertical bar we've discussed (or better yet a pair of bars). In lieu of their being required, there is nothing stopping the car owners from getting together and agreeing to use such designs voluntarily.

It's your butt at risk, so you have only yourself to blame if you decide not to do something and it comes back to bite you later.

Soory NA didn't mean to confuse you,Yes do all layers at once , what I was trying to say was that in a new construction some guys bag the first layer or two to debulk it then add core and susequent layers . for instance in aerospace because of the number of layers of material a certain amount has to be debulked or you would never get a void free lam,I'm sure Tom Irwin could explain better than me the process. for most race car fixes you would do all lams at the same time ,cleaning of the substrate still applies for adhesion.
Dave Craddock

I agree with Dave do all the plies at the same time. Surface prep is key to a good bond.
For Sandia Labs I did some repairs with Boron onto aluminum to 747's & DC-10's and the prep was to build a bag on the surface first and do a Phos Anodize etch. Just to prep the surface. It was not fun but it was a low PH acid and low voltage.

But keep it simple here. You do not want to layup over paint etc. I have seen many types of Kevlar weaves in DB-1 side pods even Kevlar roving. The trouble with prepping the previous kevlar is it does not sand or grind well to a "feathered edge" It's like shearing sheep with a weed whacker. When the kevlar gets abraded it goes inert but will calm down when resin is reapplyed. Sometimes when I can't get a good "scuff" in a detailed area I grit blast it with a cheap harbor frieght hand held sand blaster. that can help to get into where the frame goes across the middle of NACA.

Vacuum bagging is the best way to go but pumps are not cheap. I've heard of old refrigerator compressors converted in to vacuum pumps and work. Good excuse to get a new frost free w/ice maker for the garage.

Adding to what you already have in the way of side impact protection is a no brainer.
Kevlar will trap a lot of the outer fiberglass "shards" from comming your way in the event of a puncture. It's not going to stop 1100 lb. fully independently suspended, manned surface to surface missile.

Aircraft Spruce has a lot of the materials and the prices are not that bad for the small quantities you need.

Look for a weave with a harness count the bigger the number the better.

Josh, I got your PM, and I have what you need, but your PM box is full. If you can make space in your in-box I will send you a PM.

Thanks

Tom

See attached picture of my SE-3. I added Kevlar on inside of body panels, and attached 6061-T6 panels to the inside of frame rails.

Very Nice Bob.:checkered:

While on the subject of Kevlar the one thing that is a must for working with it is a good pair of shears. There is a lot of them avalible from different sources and I have tried a lot of them. I bought a pair at a S.A.M.P.E. convention about 5 years ago and they are my go to's for cutting kevlar. They are KAI brand modified by Garnard Hill master sharpener at Wolfe Industries in Spartanburg SC. I have only sent them back 3 times for tune up. This company invented the machine to modify the edge. They sell a special Kevlar shear but you can get the same one I have and save $ by ordering the KAI 7280 and have them modified or send you own. Make sure you send them samples of the Kevlar that you will be using. Their website show the stock shear at $60 and I think the mod is around $30 well worth it if your going to do a lot of work on the car. I send them about 10 pairs of my fiberglass shears a year. Here is a pic I took yesterday to show you

This is 5oz. plain weave, I have cut roven Kevlar no problem. I went to a supplier one time and you shoud have seen their faces when I pulled these out and cut it. If you get a pair do not use them on anything else.

Soon there will be another generation of composite cloth other than F/G, C/F, & Aramid (Kevlar) We have a patent on it, It's very cool just wait. I'm working on it.