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View Full Version : The wrong way to test an impact attenuator



JamesWolak
05-10-2010, 06:19 AM
I think I remember Mike Cook talking about how impact attenuator testing is going to end up hurting more people then helping. I am starting to agree.

http://www.youtube.com/watch?v...SPYqteE&feature=grec (http://www.youtube.com/watch?v=lLhHAR3jhrc&playnext_from=TL&videos=cy27SPYqteE&feature=grec)

JamesWolak
05-10-2010, 06:19 AM
I think I remember Mike Cook talking about how impact attenuator testing is going to end up hurting more people then helping. I am starting to agree.

http://www.youtube.com/watch?v...SPYqteE&feature=grec (http://www.youtube.com/watch?v=lLhHAR3jhrc&playnext_from=TL&videos=cy27SPYqteE&feature=grec)

Tonaka
05-10-2010, 10:11 AM
It was so much dangerous!!

And as we can see, the forces must be less than the requirement ( around 10 Gs).

fixitmattman
05-10-2010, 10:51 AM
No helmet, just like a real trooper.

Kirk Feldkamp
05-10-2010, 11:40 AM
Somebody needs to frame by frame this video! That kid almost ate steering wheel. He might want to pull those straps a little tighter next time!

-Kirk

Zac
05-10-2010, 12:21 PM
Something even stupider than this:

http://www.youtube.com/watch?v=JBnnLQaZqg8&NR=1

I'm impressed.

TorqueWrench
05-10-2010, 01:51 PM
No fire suit, no helmet, no gloves, no wrist restraints, speed based off a motorbike running next to the car, super loose belts and stuff flying around my head that gets knocked loose. Thats just the way I like to test my impact attenuators.

/sarcasm

In all actuality, this is why my team did our slow speed crush test instead of dropping weights or anything to do a high speed test. Its nice to know what happens in a real life crash, but its not worth the risk of someone getting hurt in the process if you don't have proper facilities to do so.

RollingCamel
05-10-2010, 02:14 PM
300 kgs was quite problematic and dangerous. We had weights in around 50-70 kg it was heavy to shovel around and the apparatus was dangerous.

I have designed our tower and checked for buckling and other stuff. However, i was worried if the structure may fail since i tried to save weight. The stress and buckling analysis was good but anything could happen. In one test our improvised quick release reengaged after the barrel fell 20-30 cm testing the structure.

Although shouting not to remove the impact attenuator by your legs some are quite stupid to do so, namely our incompetent camera man.

It was cool, but it some ppl may do stupid things and doesn't give shit about their own safety.

RollingCamel
05-10-2010, 02:14 PM
http://www.youtube.com/watch?v=C7yKoJPVRts

Adambomb
05-10-2010, 02:55 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TorqueWrench:
No fire suit, no helmet, no gloves, no wrist restraints, speed based off a motorbike running next to the car, super loose belts and stuff flying around my head that gets knocked loose. Thats just the way I like to test my impact attenuators.

/sarcasm

In all actuality, this is why my team did our slow speed crush test instead of dropping weights or anything to do a high speed test. Its nice to know what happens in a real life crash, but its not worth the risk of someone getting hurt in the process if you don't have proper facilities to do so. </div></BLOCKQUOTE>

+1

http://media.animevice.com/uploads/0/6566/181148-triple_facepalm_super.jpg

rjwoods77
05-10-2010, 08:05 PM
Even worse....

http://www.youtube.com/watch?v=JBnnLQaZqg8&NR=1

AMER
05-11-2010, 12:26 PM
well I think that you just need more members in your team for testing failure.

The AFX Master
05-11-2010, 01:18 PM
1st place for the most idiotic track test ever...

You guys deserve to be banned from competitions here, on Mars, and other galaxies thanks to being absolute morons...

/rant

JamesWolak
05-11-2010, 03:45 PM
This best part about this is they posted it on youtube thinking it was allright.

Mehul Botadra
05-12-2010, 11:43 AM
They think they're cool! :P

scotty young Taylor Race
05-12-2010, 12:33 PM
They where trying to re-create the final scene on the 1971 movie Vanishing Point where the dude drives the Cuda wide open into some bull dozers..
Just on a smaller scale I recon..

AwesomeAlvin
05-12-2010, 12:37 PM
I don't understand why FSAE wouldnt offer a IA that any FSAE team could just buy. I know its suppose to be a learning experience and all, but when it comes to saving someone's life do you honestly trust the work of a undergrad engineer? We are not allowed to make/design our own belts, nor are we allowed to make/design our own helment and race suits. Why are we FORCED to make/design our own IA, AND test it??

AA

L B0MB
05-12-2010, 05:07 PM
To turn you into an engineer http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif

fixitmattman
05-12-2010, 05:19 PM
So if all anyone does is buy and integrate parts, who's going to be left who actually know's how to design and test them.

Whis
05-12-2010, 07:37 PM
I dunno.. Maybe like the rest of the car that you have to design and build? Because, you know, the rest of the car doesn't save your life? How is any FSAE car more than 10% bought parts that were integrated?

Tom W
05-12-2010, 10:11 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Whis:
I dunno.. Maybe like the rest of the car that you have to design and build? Because, you know, the rest of the car doesn't save your life? How is any FSAE car more than 10% bought parts that were integrated? </div></BLOCKQUOTE>

Was it 2008 that a German team ( <STRIKE>Darmstadt?</STRIKE> TU Braunschweig thanks Tobias) went sideways into a concrete man hole cover and dynamically tested their side impact structure in a major fashion?

I would never say that the IA is the only part of the car that could be relied on to save the drivers life. Before standard IA's what about standard fuel tanks and standard fire walls?

Or maybe we should have standard side impact structures so that better confidence can be had in the manufacturing techniques used. Then we had better have a standard engine to make sure that it doesn't blow up, oh and a standard cooling system to make sure we don't get steam coming out of it because that could burn someone...

Whis
05-12-2010, 10:32 PM
Oh man, I love sarcastic responses to sarcastic responses to sarcastic posts. This is gonna be awwweeessssommmme.

I just fail to see how the IA is pertinent to the design of a formula car when so many teams fail to keep the wheels on the car during the first brake test.

The only reason the side impact structure works on most teams is because the tubing sized is spec'd in the rules. We sure don't have anything other than the tubing there. Maybe a radiator or two. Yeah, sure, I can see how IA design is worth it to a team that already knows how to build a formula car that works. I guess this is why FSAE has a grading system.

On the other hand.... Why can't I make my own seat belts? Why not just spec what material size, type, etc? Why can't I make my own helmet?

Or!!!! Why don't they just tell us what size of IA to use and type, etc like they do with chassis tubing? The we can do the equivalent of a structure equivalency form, impact equivalency or whatever and go that way? I fail to see why FSAE deviates from the general theme of the rules, which is spec the things that people would mess up so they can't be messed up, in this one location.

Whis
05-13-2010, 02:21 AM
Apparently my response has to get approved. I played too much buzzword bingo...

Summary: Why didn't they spec a IA size like they do for tubing with a structural equivalency form? Just call the form something else. Like 'Impact Equivalency'.

I can see it now.

Dude 1: "My 5 mph crash had way more G's than your 10 mph crash."

Dude 2: "Nuh uh! Look at my Impact Equivalency form!"

TMichaels
05-13-2010, 03:51 AM
@TomW:
We, TU Braunschweig, were the guys testing our side impact structure by crashing into a concrete man hole.
Thread is still there: http://fsae.com/eve/forums/a/t...10646541#75110646541 (http://fsae.com/eve/forums/a/tpc/f/125607348/m/75110646541?r=75110646541#75110646541)

Regards,

Tobias

TMichaels
05-13-2010, 03:57 AM
My post is also delayed, because I put the link to our thread telling about our crash during testing 2008 inside. We, TU Braunschweig, were the guys with the concrete man hole.

Regards,

Tobias

Mehul Botadra
05-13-2010, 10:52 AM
LMAO! Good way to get rid of an egoistic team member! :P

AwesomeAlvin
05-13-2010, 12:29 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by fixitmattman:
So if all anyone does is buy and integrate parts, who's going to be left who actually know's how to design and test them. </div></BLOCKQUOTE>

ok let me quote myself

"I don't understand why FSAE wouldnt offer a IA that any FSAE team could just buy. I know its suppose to be a learning experience and all, but when it comes to saving someone's life do you honestly trust the work of a undergrad engineer? We are not allowed to make/design our own belts, nor are we allowed to make/design our own helment and race suits. Why are we FORCED to make/design our own IA, AND test it??"

Ok now, every single rule in the rule book is there for safety, including rules regarding the car number placement on the car. Would everybody agree??? If you follow the intent of the rules, you pretty much have a safe car. Minus the IA. Ive been doing FSAE for 3 years, and I could tell you that some of the IA I have seen don't do squat, yet get into comp (including IA my team once used). The only reason I could see, is because they don't want to resrict monocoque nose cone designs. Well then maby teams should be allowed to choose if they should use the "standardized" IA or design/test their own.

If they FORCE us to design AND test the IA, so we could be "engineers" why don't they FORCE us to design/test helments? belts? suits? gloves? grade 8 bolts? why don't we roll our own chassis tubes and test them??? Its just a matter of time when some first year time with a time and budget crunch tries to test the IA and gets killed.

And thank you Whis for reading my entire post.

AA

Kirk Feldkamp
05-13-2010, 01:11 PM
I'm always amazed by how pumped up people get over forum debates. Chillllll guys... this is not something worth getting so worked up over. http://fsae.com/groupee_common/emoticons/icon_eek.gif

What many newer FSAE addicts might not realize is that the impact attenuator testing and report are a relatively new addition to the rules. Before, you just had to have one. I'm not sure how far back you'd have to go to where you didn't even have to have one, but my guess is not far. As you say, AwesomeAlvin, the IA's that are on the cars "don't do squat." I think based on the desired levels of deceleration and total energy absorption (per the rules), they're not expecting this thing to do a whole lot. They know full well that the primary driver protection is going to come from the chassis, plain and simple. They "force" teams to go through the process because it's an engineering competition, and this is a relatively harmless way of getting into a more complex area of analysis, without simultaneously overburdening teams. If you really want to go bananas, you can do a composite structure and go through the whole SEF process. Otherwise, the rules committee has deemed the allowable steel structures to provide sufficient driver protection given the intended competition conditions.

You're also kidding yourself if you think that a driver in one of these cars couldn't be killed at any time under 'average' testing circumstances. We've all seen enough youtube videos, and been party to enough shady testing to know that 'ideal' test facilities are not always available. But what can you do other than make sure that your own team is making smart decisions about where and how they test? I would say that given the risks associated with many other forms of racing (think karts or motorcycles), FSAE cars provides a fairly high level of protection given the speeds and obstacles involved. Would I want to take one of these things into a barrier at high speed? Hell no... but I don't think there's ANY way (within reason) to completely protect the dummies that can't think for themselves. Independent testing is impossible to regulate (duh), so appropriate protection of the drivers and spectators is up to the teams. Self preservation instincts cannot be taught, so why try to regulate it? The rules can only recommend appropriate solutions. Engineering and/or testing most anything has inherent risks no matter how you slice it.

-Kirk

Big Bird
05-13-2010, 03:15 PM
Ditto to Kirk above - both about the intent of the IA testing, and the call for bit of calm.

Regarding the original topic, that would have to be the most mind-numbingly stupid thing I have ever seen recorded within this community. Good grief, we have spanners photographed and assessed by our OH&S people just to make sure we don't hurt ourselves - and yet we have these cowboys trying something as hare-brained as that? And then posting it on You-tube? Wow, there truly are no bounds to stupidity. These guys are prime candidates for a Darwin Award.

And where the hell was their faculty advisor when all this was happening? There surely would have to be someone, somewhere in their university, who had some inkling that this was not a good idea.

I hope the SAE appropriately sanctions this mob. There are a lot of good people who do a lot of good work to make this event safe, enjoyable and educational for us all. But it only takes a few buffoons like this to undo all their good work.

The AFX Master
05-13-2010, 07:14 PM
@ Geoff...

They had taken your motto too seriously.. specially the "Break It" part.

Michael Royce
05-13-2010, 09:02 PM
Geoff,
Ahmen.

Whis
05-14-2010, 07:56 PM
Well. My post, at the very least, was not meant to sound nasty. Just writing what I think.

I think the internet is either all srs or all teh funny. Least, it comes across that way sometimes.

I disagree on the advisor. I don't know about your school, but our advisor is never there for any of our testing. We're just smart about it.

I have no idea why they thought that was a good idea.

TMichaels
05-16-2010, 02:49 PM
Hey,
just wanted to add that it is common for two teams or more in Germany to develop the IA together, test it one time at a lab of our(FSG/FSE) technical partner, the DEKRA, and then hand in a nearly identical IAD. This sounds like a good compromise since the IA is not a performance sensitive part and it is tested in a very trustworthy way.

Regards,

Tobias