Jim,
FEA is the acronym for finite element analysis and it is a program where a computer model of the component or part in question is subjected to various scenarios. In simple terms (and this is a basic overview) the tubular frame is broken down into its components with each tube junction assigned a code and the mechanical properties of the tubes connecting those points are input into the program. In the case of the analysis of the Force incident a "vibration module" was also used in addition to the standard program into which are input bending and twisting moments. The basis of these inputs are data that was gathered by putting load measuring modules on chassis in competition.
In the case of the Force episode it appears that the failure of the left rear tire induced the rotational oscillations which appeared to induce the failure of the frame rails. The additional X bracing in the top and bottom of the cars is designed to damp those oscillations and spread any loading throughout the frame.
By the way, a couple of crew chiefs that i have spoken to feel that the new bracing may have made the cars more consistent.
As for viewing the results of the FEA deal you will probably have to spend $50,000 plus on the software and then find a funny car to instrument so that you can input the correct values.

Roo

Roo

Roo; help me out here. If I walked into the room with that chassis up on the screen, carrying my three pound shot mallet to help induce a simulated tire shake vibration, do you think the monitor would live?

Bob

__________________
Bob Meyer Race Cars / San Diego
2005 Our 40th Anniversary

no Bob because it makes more downforce than any mallet ever made to date...

[quote=Keith Burgan;103283]Jim,
FEA is the acronym for finite element analysis and it is a program where a computer model of the component or part in question is subjected to various scenarios. In simple terms (and this is a basic overview) the tubular frame is broken down into its components with each tube junction assigned a code and the mechanical properties of the tubes connecting those points are input into the program. In the case of the analysis of the Force incident a "vibration module" was also used in addition to the standard program into which are input bending and twisting moments. The basis of these inputs are data that was gathered by putting load measuring modules on chassis in competition.
In the case of the Force episode it appears that the failure of the left rear tire induced the rotational oscillations which appeared to induce the failure of the frame rails. The additional X bracing in the top and bottom of the cars is designed to damp those oscillations and spread any loading throughout the frame.
By the way, a couple of crew chiefs that i have spoken to feel that the new bracing may have made the cars more consistent.
As for viewing the results of the FEA deal you will probably have to spend $50,000 plus on the software and then find a funny car to instrument so that you can input the correct values.

Roo

Thanks for that information! Couldn't the guys with the $50K software just send me a pdf? -

__________________
"The Counterfeiter"

Come on Keith.

How can they say this? Based on a "model" on the screen? A program is only as good as the programmer. That's why I said before, computer models don't make runs, funny cars do. I was told the pipes that broke on Hights car on black Monday showed up as blue (low stress) in the model. Interesting how the computer model verified these pipes with the least amount of measured stress yet they are the ones that broke.

And when Del Worsham was knocked unconscious by a catastrophic tire failure in Reading you are saying all those engineers have direct knowledge of the physics involved in Del's deal and that it could not possible have been as bad as Force's just because his 4130N Grant Downing built chassis stayed together and Force's didn't? And everyone came to this conclusion how? Keep in mind he hit the wall after being knocked out and the chassis still survived!

Sorry, all the fancy wording by the finest engineers (some of whom come to their conclusions by asking the chassis builder what they are supposed to think) are trying to make this go away and it's not going to happen.

Since Nixon Watergate I haven't seen such a rush to cover someone's a$$ as we are seeing now. Unfortunately, we all witnessed John Force just about kiss his good-by. Armed with information from those finest engineers, Force has already said he will "never" have another heat treated tube in any of his frames. What does he know that you don't?

I know what he does that you don't. He sticks his kids and himself in them. And he has made his feelings on the issue perfectly clear, seems to me.

No offense, but...sorry. Only the fires here in So Cal have more smoke than we're being fed on this.

RG

Randy,
Jim asked what FEA was and I explained it with an example of the results from an analysis. If it was just Murf's engineers that were coming to these conclusions I could possibly support your premise but the Ford guys have been heavily involved and a huge amount of input on all aspects of the design, materials and construction of the chassis has come from John Medlen. Have you talked to John about what he has researched? It could be a very long conversation as he has been very busy.
I never referrenced Del's episode, just Force's and the knowledge that I have of it and the subsequent analysis.
There is no smoke here, just facts. I don't know why JFR is the only team that is having problems but Tony Pedregon just cycled out a chassis with around 125 runs on it without breakage and I would guess that some of the other front runners are in the same situation. Did Ashley Force's car come apart when she slammed the wall at Seattle? Did Hight's car suffer massive main frame rail failure when he hit the wall at Topeka? (twice). It killed the frame forward of the motor plate but that was the car that they ran from the Indy test session on.

Roo

Damn...now that is saying like it is. I've always liked Scelzi, and he has never been one to mince words.