structural crash worthiness standards

[stroker]

When the SCCA specify a certain steel/diameter/thickness for frame design, are they doing so because they have actual data from TESTING or are they just working from previous crash experience ("Well, JoeBob's frame didn't fail so there's no need to increase that tube strength...")?

Anyone know where I can get more information on this?

[chop456]

Don't know, but if you're not already familiar with the case, look up "Mike Gagliardo".

[Napoleon]

Having raced in SCCA for 15 years or something like that I am almost certain they do not have test data they are basing it on, although that is not to say the standards may not be based on sound engineering data. The GCR sets a bunch of standards for the roll cage and the thickness is just one of them.

[G.]

Don't know, but if you're not already familiar with the case, look up "Mike Gagliardo".Is that the family that had the protest banner flying over RA in (I think) 2002?

[SteveH]

^ yes

[Indy]

I don't remember that. Why did they fly it at RA (he was killed at Mosport)?

Are you alluding to the way the frame came apart in his car? I am aware that his family sued, but what was the outcome?

[stroker]

I don't remember that. Why did they fly it at RA (he was killed at Mosport)?

Are you alluding to the way the frame came apart in his car? I am aware that his family sued, but what was the outcome?

http://www.motorsportmemorial.org/focus.php?db=ct&n=266

which is interesting, but that strikes me as a failure of the sanctioning body to enforce the rules (assuming the allegations are true)...

My question deals more with how the standards are created than how they're enforced. For example, let's look at Formula SAE. The purpose of the SAE program is to provide a training opportunity for aspiring engineers in the building of an autocross car. Even I know that you can't take that car, remove the restrictor and then go roadracing with it. The cage is almost certainly not strong enough for the undoubtedly higher speeds that roadracing would entail.

Regardless of that (hat tip: Indy) the question is, how would an organization like SAE come to a conclusion of what tube alloy/diameter/thickness would be sufficient for autocrossing vs SCCA determining what tube alloy/diameter/thickness would be appropriate for a road racing chassis? Is there any documented and published science with this, or is it based almost exclusively on what's worked in the past?

Somebody here has to know, don't they? ? Does Rocketdoc ever wander through?

[Andrew Longman]

I'm not an engineer and I didn't even stay in a Holiday Inn Express recently, but I would think it would be a fairly straight forward engineering exercise to calculate strengths needed in a frame and cage given the likely speeds and mass of the cars likely to compete.

From that there are readily available data on the loadings of various tubings and metals, based on actual tests from which to create the final design.

Over time and with use the design and standards might be tweeked and modified. I know NASCAR has added and moved bars here and there based on actual use, sometimes as a result of a tragedy.

Think of it this way, they don't crash test bridges before they are put in place but they design them off verified models and standards. And when a bridge actually fails that learning is put back into the models and standards.

[Napoleon]

I'm not an engineer and I didn't even stay in a Holiday Inn Express recently, but I would think it would be a fairly straight forward engineering exercise to calculate strengths needed in a frame and cage given the likely speeds and mass of the cars likely to compete.

Well put. This is what I intended to imply in my response. I would think it is the kind of thing a senior in engineering school could calculate based on publically availible data.

[stroker]

I'm not an engineer and I didn't even stay in a Holiday Inn Express recently, but I would think it would be a fairly straight forward engineering exercise to calculate strengths needed in a frame and cage given the likely speeds and mass of the cars likely to compete.

From that there are readily available data on the loadings of various tubings and metals, based on actual tests from which to create the final design.

Over time and with use the design and standards might be tweeked and modified. I know NASCAR has added and moved bars here and there based on actual use, sometimes as a result of a tragedy.

Think of it this way, they don't crash test bridges before they are put in place but they design them off verified models and standards. And when a bridge actually fails that learning is put back into the models and standards.

Okay, I had assumed as much. Why then, am I finding it so hard to locate those specifications from the SCCA posted online somewhere?

Or do I need to stay at a Holiday Inn?