I can speak for the TEEX Recon class and tell you we cover system based concepts, elasticity, momentum, energy and restitution; key concepts in the analysis of a low speed collision in terms of AR. No, there's not much on bumper EA systems in THAT class or the specifics of low speed injury potential but while the former is a detail left to our "Low Speed" class, the latter is not actually so much AR as biomechanics so there wouldn't be. Ther's a perfect example, the Recon class is in the underlying science and concepts, the "Low Speed" class covers EA systems...that means one needs at least two classes in AR to be reasonably conversant in csome of these concepts!
With respect to how one attains a sufficient level of training in reconstruction, I think self study is, at the very least, dangerous given the current and developing state of the law with respect to decisions such as Daubert and Carmichael. Carmichael is a good example. Engineers with nothing more than traditional engineering training are at risk as much as police with nothing more than their academy or basic training. Misunderstanding or misrepresenting ones qualifications is to be on an equally dangerous footing.
Finally, understand that the SAE hasn't done the barrier crash tests. When you wrote ".... I do not believe that the SAE barrier data makes sense for low speed crashes..." understand that there is no such thing. The NHTSA contracts for higher speed barrier crash tests and public and private entities do them but not the SAE itself. Members of the SAE and other associations have done barrier crash tests and while those tests may be REPORTED in SAE published technical papers written by the specific authors, the SAE itself, to my knowledge, has never run barrier or any other such crash test.
Certain groups within the "AIRP Committee" (nod to its varying name evolutions over the years) have done ABS tests and other testing, but there are no "SAE barrier tests." This is an important distinction. SAE papers are technical reports of the activities and theories of the members or contributors. Every paper runs with a qualifier that it's not the opinion of the SAE, blah, blah, blah.
Low speed barrier crash tests - like those conducted by Siegmund, et al and reported in SAE papers - DO make sense in low speed crashes. They are very much applicable. You want to know what delta-V relates to how many inches or mm compression of an EA piston, the barrier test works just fine. Want to find a damage threshold? Progressive barrier tests to find that threshold work just fine when compared to real world crashes. That's been demonstrated valid time and again.
Your reference to the course material from our Analysis of Low Speed Collisions course at section 2 page 2 is lost on me. That page contains a discussion of the term "low speed" as I tried to suggest in a previous post and reinforces the idea that the underlying physics are sound and can be applied, within limits equally to "higher speed' collision as they might to "low speed collisions." A difference, for example, being, for example, that restitution plays a larger role in "low speed" collisions than "higher speed collisions."
Re read Siegmund and King and that series of SAE papers. I think you'll see that the conclusion is that barrier testing is very useful when compared to real world crashes. Higher speed barrier tests compare to higher speed car-to-car crashes. Lower speed barrier tests compare to lower speed car-to-car real world crashes.
- Rusty
Rusty Haight
rustyhaight@worldnet.att.net
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