Structural Integrity of Carbon Monocoque chassis like the Enzo Porsche GT? Dangerous?

Then there was that hockey player. Heatley?

That 928 was not going fast compared to the Enzo.

 

The last Ferrari running won't be one of the Supercars. It will probably a 250.

 

True - but I posit that someone driving an Enzo enduring the exact same collision would not survive.

 

What do you base that conclusion on?

It's all a matter of balancing out the cost to fix the thing vs what it is worth when fixed.

Dropping $300-400k to fix a $700k F50 likely isn't going to happen. But if enough F50's go away and the price goes up, then it becomes worth it to somebody to fix the car (ie $300-400k isn't as big of a deal if the car is worth $3M).

 

is that the determining factor if one can drive an Enzo??

That "ten year" mark makes absolutely zero sense. Shouldn't severity of use be the "factor"? What if it is barely used???

+1

 

Actually, from I have read and seen, they flew the plane by the book. They simply ruddered it around like you would any aircraft, stomp on the right pedal when you wanna go right. It just turned out that the hydraulics work very efficiently, and flapping the rudder back and forth hard overstressed it. But it showed a problem with composites, that they are very unforgiving. Aluminum would probably have stood up better, and fatigued over time if watched. Very seldom does an airplane made of aluminum suddenly fail. There was almost always something noticeable beforehand had someone been watching. The carry through spar on a Bonanza comes to mind. But like anything else, its a new technology that is still being learned, and unfortunately, failure is sometimes the greatest teacher.

 

The same is said of timing belts. The type of usage is never known unless witnessed. Clients are rarely if ever forthcoming about that anyway. A line needs to be drawn somewhere. In street cars the F50 was a first for Ferrari with CF tub. There is no database so a number was picked. Race car experience was not a contributor to the database. How many F1 tubs last out the year? And if they do, so what? There is an all new car next year.

 

I have every confidence that Ferrari's price to tool up and make more tubs will go up at a faster rate than the cars ever hope to and it is not the only short lived component of the car anyway.

 

This is completely wrong. Read the NTSB report www.ntsb.gov. Here's the first half of the final press release I found from them on this incident.



NTSB News
FOR IMMEDIATE RELEASE: October 26, 2004 SB-04-31

NTSB SAYS PILOT'S EXCESSIVE RUDDER PEDAL INPUTS LED TO CRASH OF AMERICAN FLIGHT 587; AIRBUS RUDDER SYSTEM DESIGN & ELEMENTS OF AIRLINE'S PILOT TRAINING PROGRAM CONTRIBUTED

Washington, D.C. - American Airlines flight 587 crashed into a Queens neighborhood because the plane's vertical stabilizer separated in flight as a result of aerodynamic loads that were created by the first officer's unnecessary and excessive rudder pedal inputs after the aircraft encountered wake turbulence, according to a final report adopted by the National Transportation Safety Board today. The Board said that contributing to the crash were characteristics of the airplane's rudder system design and elements of the airline's pilot training program.

At about 9:16 a.m. on November 12, 2001, flight 587, an Airbus A300-605R (N14053), crashed in Belle Harbor, New York shortly after taking off from John F. Kennedy International Airport on a flight to Santo Domingo. All 260 people aboard the plane died, as did five persons on the ground. This is the second deadliest aviation accident in American history.

The aircraft's vertical stabilizer and rudder were found in Jamaica Bay, about a mile from the main wreckage site. The engines, which also separated from the aircraft seconds before ground impact, were found several blocks from the wreckage site. The Safety Board found that the first officer, who was the flying pilot, inappropriately manipulated the rudder back and forth several times after the airplane encountered the wake vortex of a preceding Boeing 747 for the second time. The aerodynamic loads placed on the vertical stabilizer due to the sideslip that resulted from the rudder movements were beyond the ultimate design strength of the vertical stabilizer. (Simply stated, sideslip is a measure of the "sideways" motion of the airplane through the air.)

The Board found that the composite material used in constructing the vertical stabilizer was not a factor in the accident because the tail failed well beyond its certificated and design limits.

 

There has been some very good information on this thread and some very bad information.

I guess some people are scared of what they don't understand.

 

"...Give that man a woman in the balcony". - Groucho

 

You are completely off base. The components failed well past their design limits. Even if an aluminum or steel component were designed to take X amount of load, it may take 1.5X due to built in margin of safety, but at 2X or 3X it WILL fail.
Seems like people fail to understand plain and simple that carbon composites are undoubtedly stronger than metal equivalents of the same weight. Composites are generally made lighter, so the point of failure may only be slightly higher than metal, but could fail with worse consequences if its different deformation properties aren't taken into account. It's definitely not the solution to end all other materials, as like anything it has pro/cons.

 

I think most people do get the fact that composites are stronger than metals of the same weight. Thats not the real question. The problem seems to be,that when composites fail, they do in spectacular fashion. Most metals will deform, not simply explode. I'll take a deformed cage, thank you.



Darrell.

 

Who is the NGC? Why is there conclusion worth more than the NTSB?

Have you read the NTSB reports?

http://www.ntsb.gov/events/2001/aa587/default.htm

Specifically you're looking for some of the transcripts - trans_021031.pdf

Making a blanket "composite broke, metal didn't" is pretty much as misleading as it can get.

 

I couldn't agree with you more. Even though everyone is entitled to an opnion, it seems prudent not to form one based on ignorance.

 

I could write a book here about this....but I wont.

I have designed carbon composite chassis in the past. The failure mode and impact energy absorbtion and deflection characteristics can all be tuned at the design level with either composites or metal structures.

The example of the Enzo in milan is not good, anly because that crash would have destroyed ANY vehicle, made from any material. In other Enzo crashes, the passenger cell seperated from the drivetrain as designed to do and the drivers all walked away (or ran in eriksons case). The material of the vehicle is a moot point in that case.

The point of using carbon composites is strength and stiffness to weight, as well as the ability to tune the properties of the carboin laminate in ways that metals cannot be tuned or shaped. Composites open huge doors in allowing freedom of design due to their greater strengths and abilities.

The future is not in going back to welded steel frames like 308's. The virtual and physical testing carried out in current vehicle design is light years ahead of the last generation of cars and supercars. You can relax.

If the idea of a composite chassis spooks you, there is always the lovely aluminum chassis F430 or 599 to spend your nickel on.

Cheers
Eric

 

Have you read the NTSB report or not?

 

Hmmmm;

There were fears that the composites were faulty because they are used in other areas of the plane including the engine mounting and the wings, however examinations of construction and the materials gave the plane a clean bill of health."

Again, NTSB report? 15 minutes of your time will give you all the information you want.

Maybe we can post some links to some wikipedia articles showing planes that fell out of the sky because of various Al and steel failures, but that doesn't really tell us anything about the materials used or even why they failed.

You can kick and scream all you want, but that doesn't change your ignorance of the subject.

 

So did you read the NTSB report, especially the multi-page testimony about the composites? Yes or no? We all know the answer by now, so you can just say it.