You buggers... (FSG)

[markocosic]

They snuck some new supplementary regs in on Tuesday:

Revised FSG Supplementary Regs (http://www.formulastudent.de/events/event-2007/rules/)


Rule 3.3.6.3 Impact Attenuator *Change from 1.2. to 1.3.*

In case of using a foam filled impact attenuator or a honeycomb impact attenuator, a 1.5 mm solid steel metal sheet (per Section Rule 3.3.3) or 4.0 mm alluminium metal sheet must be integrated in the impact attenuator. The metal sheet must have the same size as the front bulkhead. The metal sheet can be welded or screwed by using 6 mm Grade 8.8 bolts to the front bulkhead.

That'll annoy some of the composites folks, given you can't sturctural-equivalency this one away.

Us? Guess who has a dirty great big front bulkhead (540mm wide at the top, 350mm at the bottom...) What a kg or two between friends anyway! http://fsae.com/groupee_common/emoticons/icon_eek.gif

[markocosic]

They snuck some new supplementary regs in on Tuesday:

Revised FSG Supplementary Regs (http://www.formulastudent.de/events/event-2007/rules/)

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Rule 3.3.6.3 Impact Attenuator *Change from 1.2. to 1.3.*

In case of using a foam filled impact attenuator or a honeycomb impact attenuator, a 1.5 mm solid steel metal sheet (per Section Rule 3.3.3) or 4.0 mm alluminium metal sheet must be integrated in the impact attenuator. The metal sheet must have the same size as the front bulkhead. The metal sheet can be welded or screwed by using 6 mm Grade 8.8 bolts to the front bulkhead. </div></BLOCKQUOTE>

That'll annoy some of the composites folks, given you can't sturctural-equivalency this one away.

Us? Guess who has a dirty great big front bulkhead (540mm wide at the top, 350mm at the bottom...) What a kg or two between friends anyway! http://fsae.com/groupee_common/emoticons/icon_eek.gif

[B Hise]

I will say this. If you plan to go into racing, prepare to put up with seemingly nonsensical or irritating proclamations from the governing body. Someone somewhere had their reasons and regardless of whether or not they have any sense, the participants have to follow the rules. I guess it can't be all fun.

In any event that rule is a pain in the ass.

-Bryan

[PatClarke]

Marko,
I understand you have an issue..BUT!!

The way to handle this is to open a dialogue with the organisers, not invite ridicule of the competition or their organisers on an unofficial public forum!

FSG is a new competition, and has some input to the rules from ADEC, who know more about crash attenuation than all of us. If you have an issue with the FSA rules revision, then ask for it to be looked at.

You will not get an official statement from the organisers on here, so I suggest you log your complaints at www.formulastudent.de (http://www.formulastudent.de)

Pat

PS, Where did you get the idea that I don't like Torsens?? What I don't like about Torsens is the lack of knowledge about how they work by so many teams who use them.

PC

And, after all, you don't have to go to Germany if you don't like the rules!!

[terra_dactile]

Marko,
We at ETS did many impact tests for the safety requirements of last years competition, using a pendulum setup with accelerometers and a high speed camera, when we test with foam filled thin layer carbon impact attenuators the foam hardly did anything, it crushed the whole nose and had a very high peak of g at the end when the pendulum structure finally hit the wall with energy left. The foam just pushed threw or mock up empty bulkhead, meaning that unless the foam has a structure behind it to absorb the energy then it does not help take the impact.

The second point is that they only mention the attenuators that have foam filled or honeycomb. If you make a light structure with carbon fibre or fibre glass then you would not need to meet the requirments mention in your post above, meaning you would not add unneeded weight to your car.
If i understand correctly when the say honeycomb they do not mean honeycomb that is in between layers of carbon in a nose, used as core to stiffen the nose cone in layup such as prepreg.

Best regards,

Jude Berthault
ETS FSAE 2003-Current
Vehicle Dynamics Leader

[Welfares]

Saying "foam is no good at absorbing impact" is like saying metal is no good for corrosive enviroments. You would then say, what about aluminium/stainless/titanium etc.

If you were using the foam out of the cushions on your couch (i know you didn't, i'm just highlighting the difference) i can see how it would do nothing, however, if you used the right stuff, you could make a foam attenuator that would be stronger than the nose of your chassis.

We use a 2 part expanding foam for ours, and we did a fair bit of testing on different types to get one that did the job right.

And i'm sure the german officials have a good reason for the steel plate. They seem to have it together over there.

[terra_dactile]

Welfares,
I never said foam was not good at absorbing impacts, i said that the rule makes sense because unless there is a backing plate to resist the foam from just pushing threw and hitting your feet then it serves no help during an impact!

Jude Berthault
ETS FSAE 2003-Current
Vehicle Dynamics Leader

[markocosic]

Err, sorry folks: More of these required: http://fsae.com/groupee_common/emoticons/icon_wink.gif http://fsae.com/groupee_common/emoticons/icon_wink.gif http://fsae.com/groupee_common/emoticons/icon_wink.gif http://fsae.com/groupee_common/emoticons/icon_wink.gif http://fsae.com/groupee_common/emoticons/icon_wink.gif I think! 'Sneaky buggers' just gets people reading the post in case they hadn't checked the FSG site in the last couple of days, not a complaint at all. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Mandating the plate is a good idea IMO: 1) prevents the impact attenuator punching through the front bulkhead opening and 2) dishing the plate both absorbs non-trivial amounts of energy and gives the 'crushed' impact attenuator space to sit in behind the front bulkehad, potentially shortening the nose length required on the car. (it's made our plate thinner - http://fsae.com/groupee_common/emoticons/icon_smile.gif but taken out all the holes http://fsae.com/groupee_common/emoticons/icon_frown.gif )

[Welfares]

Okay, fair point Terra, we run a tub that has a bulkhead anyway, so its not something we thought of.