Why has land speed racing ignored composite construction?

[PorkPie]

In January 1981 the first McLaren carbon chassis was finished built, Lotus was nearly finish.....just history...

[desotoman]

I agree. So why Franklin does you post say "Re: Where are the land speed racers in their twenties and thirties?" That is a different thread on this forum.

Tom G.

Because someone moved to the right place for him.... 

Thanks Mike. Now I understand.

Tom G.

[Glen]

Sure seems like most of the day has been spent arguing with ratliff.

[jdincau]

     There are several problems with Composite construction:

     The cost of the materials is much greater than steel tube. I spent $250 in materials alone making .050" thick carbon fiber - epoxy resin inner wheel pants for my brothers streamliner and they are non structural components. I could build half the chassis out of 1 5/8" DOM steel for that.

     The skills and tools required to build a composite structure from someone else's pre-engineerd set of instructions is not beyond the backyard builder.The engineering required such as materials, resins, plys, ply orientation, local reinforcement for attachments, cure times and post cure bonding of Assembly's to name a few is not, unless he is associated with or is himself a composites structural specialist. Each composite structure is a one off design case and there are few generalizations that can be made unlike a fully triangulated steel tube structure. Remember we are talking about a structure protecting someones life here not a body panel, fairing or wing.

     Certification of a design requires either computational structural analysis or crash testing both of which are beyond the backyard builder and any current LSR sanctioning body.

     I speak with some experience, 34 years at Lockheed working with some of the best engineers in structural analysis and design.

[Ratliff]

     There are several problems with Composite construction:

     The cost of the materials is much greater than steel tube. I spent $250 in materials alone making .050" thick carbon fiber - epoxy resin inner wheel pants for my brothers streamliner and they are non structural components. I could build half the chassis out of 1 5/8" DOM steel for that.

     The skills and tools required to build a composite structure from someone else's pre-engineerd set of instructions is not beyond the backyard builder.The engineering required such as materials, resins, plys, ply orientation, local reinforcement for attachments, cure times and post cure bonding of Assembly's to name a few is not, unless he is associated with or is himself a composites structural specialist. Each composite structure is a one off design case and there are few generalizations that can be made unlike a fully triangulated steel tube structure. Remember we are talking about a structure protecting someones life here not a body panel, fairing or wing.

     Certification of a design requires either computational structural analysis or crash testing both of which are beyond the backyard builder and any current LSR sanctioning body.

     I speak with some experience, 34 years at Lockheed working with some of the best engineers in structural analysis and design.

How much of that 34 years was spent doing, for example, moldless composite construction?

You can build a lot of composite structure for what it costs just to buy a good TIG or heliarc welder.

None of the steel tubing spaceframes in SCTA are certified based on any sort of engineering analysis. They're all one off designs where the only requirement is they use tubing of the specified diameter and wall thickness with the requisite number and placement of hoops in the rollcage. But if your fully enclosed vehicle has two wheels instead of four, you don't even have to use the same size tubing for the same weight vehicle going the same speed.

[Glen]

This is the same guy who said a plywood  car was safe if he built it.

[Dean Los Angeles]

Sure seems like most of the day has been spent arguing with ratliff

No, to argue you have to have someone of similar intelligence.

[jdincau]

>>How much of that 34 years was spent doing, for example, moldless composite construction?

I built two moldless composite structure wings for a successfull Top Alcohol dragster in the 80's. I scaled Rutans Long-easy canard design down using a different airfoil. The first one failed at the attachment points because tire shake was much more violent than we assumed (no real data available). The second was the one we used to win the TAD class at the NHRA US Nationals in 1988.

>>You can build a lot of composite structure for what it costs to buy a good TIG or heliarc welder.

True but you can also build a lot of steel structure for what it costs for weighing scales, fabric shears, brushes, squeegees, rollers, mixing cups, rubber gloves, peel ply, vacuum pumps, mold release, bagging materials, wire foam cutter, rheostat for said cutter and all the other sundry tools needed for composite work. All process require tools, some composites tools may be cheap but there are a lot of them and a lot of them are consumeables. And by the way TIG and Heliarc are the same process.

>>None of the steel tubing spaceframes in SCTA are certified based on any sort of engineering analysis. They're all one >>off designs where the only requirement is they use tubing of the specified diameter and wall thickness with the >>requisite number and placement of hoops in the rollcage.

Technically true, but the generalized tubing diameter, wall thickness, tube placement and reinforcement requirements can give the sanctioning body confidence that the structure will protect the driver in a crash. Such generalized rules don't exist for composite structures.

[Stan Back]

Come on Glen -- don't you know plywood is composite wood?

[John Romero]

words...

Franklin, The title of your post is "Why has land speed racing ignored composite construction?". Of course this title is biased as it assumes that land speed racing has ignored composite construction. I have not ignored it. I have built two different full carbon composite vehicles over the last 20 years for different competition series so I didn't ignore it. I chose to do my car a different way. And the reality may be that it could have been bypassed for any variety of reasons. Naming your thread this way just sets the stage for yet another argumentative thread, something like your 84th this month alone.

If you had named it "Can composite construction be used effectively in land speed racing?" or maybe if it was titled "What type of tech inspection procedures could validate the safety of carbon construction vehicles" a discussion could have followed exploring the unique build procedures used in cc structures. Maybe you could have named it "is it easier and cheaper to build a composite construction chassis versus steel tubing?"

All of these could have got a nice discussion going.

Something tells me the wheels are wobbling and about to come off this bus.

[Ratliff]

Semi-monocoque composite dragster from 1977.

Frame was 1 inch diameter .049 wall chromemoly tubing with fewer uprights and lateral members than normal where the foamcore sandwich composite body served as a stress-carrying part of the chassis.

[willieworld]

franklin  --you are talking about building the car of composite not just the body --there is no way to look at someones project and tell if it is safe--on a tube car you can measure and see and sonic check when in tech --- doing composite right requires more skill and equiptment than most lsr people have  ( that will start an arguement --SORRY )---and even if you use composit you will still need a tig welder --the problem with composites is also hanging all of the steel parts it has to be done correct---i use  to have a fiberglass car repair business and you wouldnt some of the work i saw--any way just emagine the mess at tech    ---willie

[Glen]

Willie, have you seen the pictures of his famous propster.

[Ratliff]

franklin  --you are talking about building the car of composite not just the body --there is no way to look at someones project and tell if it is safe--on a tube car you can measure and see and sonic check when in tech --- doing composite right requires more skill and equiptment than most lsr people have  ( that will start an arguement --SORRY )---and even if you use composit you will still need a tig welder --the problem with composites is also hanging all of the steel parts it has to be done correct---i use  to have a fiberglass car repair business and you wouldnt some of the work i saw--any way just emagine the mess at tech    ---willie

In the dragster there was no separate body. The body was part of the structure.

[Ratliff]

Picture of the Amsoil racer under construction. The fuselage was foamcore and fiberglass sandwich composite. Carbon fiber was used only in the wings. The Amsoil racer was the first all sandwich composite vehicle in which the occupant walked away from a 200 mph crash.