Hi everyone and welcome to the new forum.My question is with crush points. The energy result from crush points is this Kinetic Energy, and if so then the impact speed is calculated from this number?I hope I am right in what I am saying.V=sqr(2*J/W)J= joulesW= weightPlease let me know if I am right with this, thanks.
Thanks Jim, I did not know that it came out in inch pounds. So that makes a big difference to my answer.Yes I know that you must use a simultaneous equation and a quadratic equation to solve for vehicle to vehicle collisions. But the info you have given will help a lot in solving the question. One other thing I do not understand is why is it that V=sqr((2gKE)/W) in imperial, but when you use metric V=sgr((2KE)/W) there is no multiplication by gravity in metric?? Thanks again.
partridge512 wrote:So for an engineer new to the accident reconstruction filed, what are great intro thru advanced training organizations ?I just purchased the Traffic Accid Recon by L.Fricke but it's copyright 1990 so a couple of workshops seem like a good idea. thanks
I just purchased the Traffic Accid Recon by L.Fricke but it's copyright 1990 so a couple of workshops seem like a good idea. thanks
I've attended both N'western University and IPTM courses and, in my experience, I think both institutions have something to offer. IPTM classes tend to be more "police-based", which is actually some benefit to an engineer who is unfamiliar with police methods. From attending IPTM classes, I have gained some understanding of how police officers are trained to approach accident analysis without attending a police academy. This has been valuable beyond measure, but in an indirect way. This is not to say that IPTM classes are not based upon sound engineering, but that there is a practicality in method that IPTM does a very good job of presenting (we engineers have a tendency to over-think stuff and work up calc's like we are building pianos or something). I have had some very good instructors at IPTM, and some that were not so great, but apart from my criticism in the previous post, overall I think the quality of their instruction is high.
The perspective that IPTM generally does not present is one that seeks to identify problems with the design, maintenance, or operation of highways as a causative factor in traffic accidents. Since they are police oriented, they tend to look for people to find at fault rather than things to find fault with. As a result, civil litigation tends to be less emphasized than criminal prosecution. This is only a tendency and varies greatly with the particular instructor.
I attended N'western TAR 2 a long time ago, so it might have changed considerably since then. I noticed that they now have an online version of TAR1 that one can take at their own pace, so that seems pretty simple (except for that $1000.00 tuition!). Again, their clients are mostly police officers so they tend toward that perspective, but, IMO, not as much as IPTM. They also offer courses in highway design and traffic engineering so they have staff knowledgable about design defects and related subjects.
If you are already familiar with calculus, mechanics, and vector dynamics, then the basic courses will be very tedious to some extent, and I would suggest looking into N'western's online version of TAR1. The mathematics review portions were especially rough for me to sit through because they have to make sure that their students are familiar with some very basic trig and algebra. The basic at-scene course will also have some review info if you have any surveying experience, but you will need it for tiremark identification and other invaluable skills.
There are some other organizations that offer courses, but I have not attended any of them. I know that N'western and IPTM are the most well-known as far as accident reconstruction training goes. I think either one will present a solid foundation, but there really is no substitute for good critical thinking skills and hands-on experience in working with crashes.
It really comes down to which is more convenient for you to attend. I hope this helps, and remember that my perspective is only one among many others who have attended both institutions. You might want to get opinions from other members before making a final decision.
P.S. Fricke's book is still an accident reconstructionist's best friend, even though some of it is not considered state-of-the-art. Even so, physics is still physics and falling objects still fall, even since 1990. I still refer to the blue book probably once a week and have for many years. I wish they'd publish an update...