WRC Deaths

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Iowa999

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john vanlandingham
x%/foot is X% or whatever per foot..

[bold added]

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john vanlandingham
I used / as "or"..when i write dimensions I write 0.966"/22mm OR

Hey Professor you and your suck-buddy troll friend are so brilliant that you don't notice "should" and "or whatever".

You dumb cunt the POINT was that there is NO method at all to think about strtch.

No units of measurements stated--just the same stupid blunder when you came and wrote all you blather about the junk on your dumb car and neglected to state what units---a typical jerk-off amatuer poser mistake.

Fucking autocrossing wanker.
Get back to class, Prof

For a guys so full of himself you sure seem like your students say.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Option 1. Admit that it was just a guess that turned out to be wrong. Move on with life, maybe with a bit more earned respect for the admission.

Option 2. Pretend that we misunderstood what was meant, then flat-out lie about it, then switch to childish insults, leaving everyone wondering how often previous claims have been complete and utter bullshit that were never corrected.

Care to try again, maybe this time not using the patented JVL two-tailed coin to make the decision?

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deaner
I love lamp.

Ha!

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john vanlandingham
Main point is we cannot say without data, so there must be some other way to try and learn: praxis. And observed results.

This is data, John, and is derived from observed/measured results, so.....?? You are uncomfortable with using engineering methods and data. That does not mean others cannot. We all have strengths and experience in different areas.

I appreciate Klim presenting the links; that is the type info that popped in my head as being needed to help answer the question on the % belt stretch quesiton.....

BTW, the % belt stretch question itself a very rational question IMO. Let's look at it this way: The stretch is indeed non-linear. The load per any given length (say, 1" is lower for a long belt than a short belt; that part is correctly arrived at via our intuition.

The 14' long belt sees a situation where the lower peak load per length means each inch of belt stays within the 'stretchier' portion of the curve, and sees more stretch on a per foot or per inch basis because the long belt never stretches enough to enter the 'non-stretchy' portion of the curve. So, it sees a greater average stretch per length, just the "stretchy' %/inch elongation.

Due to the 7x greater load per inch on the short 2' belt, the short belt will be quickly stretched through the 'stretchy' portion of the curve and get into the 'non-stretchy' portion of the load curve; i.e., it will 'draw up tight' and not stretch much more. The overall % of short belt stretch will be less because it actually enters the 'non-stretchy' portion of the load curve, whereas the long belt never does. (The long belt never 'draws up tight'.) The short belt sees a lower average % stretch per inch because it is the averege of the 'stretchy'% and the much lower 'non-stretchy' %.

Is this realistic? I think fairly so, though I have not really gone through the numbers. With the load size used, the G's that are readily survivable, and the difference in belt lengths, it will be fairly realistic overall, and certainly useful for seeing the overall difference in a long belt attached in the package shelf area of the car versus a short belt attached in main hoop area. The only thing I question is when/where could you possibly have a 14' long shoulder harness? 8' I can see, but 14'??

Regards, Mark B.

Hm. Load per given length? Not sure what that is. When you take a non-elastic object and put in under tension, every point between the ends of the object is under the same amount of tension, regardless of how big the object is. Tension (in a non-elastic) object is not spread across the object (like pressure might be); it is all under all of the same, total tension until something gives.

To put this another way, if you think about a one-inch piece of the belt in the middle, until something starts to stretch, that inch of belt is under the same tension, regardless of what the total length of the belt is. Only when you have reached the point where the weakest part of the belt starts to stretch does this cease to be true.

When you next add in the fact that most objects, including seat belts, are not consistent, one reason why longer belts "give" more is simply because there is more belt (and, therefore, more opportunity) to have a weak-spot. Thus, the amount of tension required to cause the first bit of stretch is lower with a longer belt. This is the opposite of what one might predict from the idea that the tension force is "spread out" along the belt.

ps. anyone else getting weird links to sites randomly inserted in their posts? and you can't edit them out.



Edited 3 time(s). Last edit at 09/27/2013 01:25PM by Iowa999.

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Iowa999
ps. anyone else getting weird links to sites randomly inserted in their posts? and you can't edit them out.

Google word ads, one of the ways the FSM recoups a small amount of money spent on hosting and moderating the site.

---

First Rally: 2001
Driver (7), Co-Driver (44)
Drivers (16)
Clerk (10), Official (7), Volunteer (4)
Cars Built (1), Engines Built (0) Cages Built (0)
Last Updated, January 4, 2015

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john vanlandingham
Blame is for idiots. losers.

Wait. Someone is PAID to moderate this train wreck?

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Iowa999
ps. anyone else getting weird links to sites randomly inserted in their posts? and you can't edit them out.

I use Adblock Plus on Firefox. It strips out most of that unwanted stuff.

But, now that you mention it, I have noticed an unusual increase in really weird responses...

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john vanlandingham
Hey Professor... suck-buddy troll... dumb cunt... stupid blunder... blather about the junk... dumb car... typical jerk-off amateur poser... Fucking autocrossing wanker...

Phew.

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Iowa999
Wait. Someone is PAID to moderate this train wreck?

No, this is an actively unmoderated forum. (sorry, forgot the [sarcasm][/sarcasm] coding on 'moderate')
There are, obviously, hosting and infrastructure costs for the site as well as occasional programming intervention so I think it's more than fair. After all, there is no free lunch!
(some might suggest clicking on the ads as much as possible to inflate the 'payback' to our benevolent overlord, the FSM.) As a clarification to the newbs around here, the FSM is not JVL but an actual third party who created the site - by pure coincidence - at the time John was banned over at Special Stage. (lest you suggest this site was made for John because he was banned from Special stage)

The reality is this forum only has a couple of rules that people are expected to adhere to. They can be found here in a now, somewhat burried, introduction to to the site and expected behavior.

In short:
1) Real Name and Real Location
2) Treat the members of the community with respect (regardless of if they deserve it or not)

OK, point 2 above is a paraphrase of the actual wording:
One sure fire way to get booted is to act consistently stupid or take personal attacks too far. Another is to whine or bullshit incessantly without contributing either knowledge or humour to the discussion.

---

First Rally: 2001
Driver (7), Co-Driver (44)
Drivers (16)
Clerk (10), Official (7), Volunteer (4)
Cars Built (1), Engines Built (0) Cages Built (0)
Last Updated, January 4, 2015

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john vanlandingham
Blame is for idiots. losers.

Edited 1 time(s). Last edit at 09/27/2013 03:00PM by Morison.

I can't wait to see what it means to take a personal attack "too far."

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john vanlandingham
Should--that's never authoritative.

Yah, my mistake.
Meant declarative, as in stating something as fact not opinion.

---

First Rally: 2001
Driver (7), Co-Driver (44)
Drivers (16)
Clerk (10), Official (7), Volunteer (4)
Cars Built (1), Engines Built (0) Cages Built (0)
Last Updated, January 4, 2015

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john vanlandingham
Blame is for idiots. losers.

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starion887

BTW, the % belt stretch question itself a very rational question IMO. Let's look at it this way: The stretch is indeed non-linear. The load per any given length (say, 1" is lower for a long belt than a short belt; that part is correctly arrived at via our intuition.

The 14' long belt sees a situation where the lower peak load per length means each inch of belt stays within the 'stretchier' portion of the curve, and sees more stretch on a per foot or per inch basis because the long belt never stretches enough to enter the 'non-stretchy' portion of the curve. So, it sees a greater average stretch per length, just the "stretchy' %/inch elongation.

Due to the 7x greater load per inch on the short 2' belt, the short belt will be quickly stretched through the 'stretchy' portion of the curve and get into the 'non-stretchy' portion of the load curve; i.e., it will 'draw up tight' and not stretch much more. The overall % of short belt stretch will be less because it actually enters the 'non-stretchy' portion of the load curve, whereas the long belt never does. (The long belt never 'draws up tight'.) The short belt sees a lower average % stretch per inch because it is the averege of the 'stretchy'% and the much lower 'non-stretchy' %.

Is this realistic? I think fairly so, though I have not really gone through the numbers. With the load size used, the G's that are readily survivable, and the difference in belt lengths, it will be fairly realistic overall, and certainly useful for seeing the overall difference in a long belt attached in the package shelf area of the car versus a short belt attached in main hoop area. The only thing I question is when/where could you possibly have a 14' long shoulder harness? 8' I can see, but 14'??

Regards, Mark B.

I don't think this is accurate. You will get the same percent elongation per a given load, ir-regarding of total length. So, if you take a belt which is 100 feet and a belt which is 1 foot, and apply the same load (say 1000lb), if the cross section area of the belts is the same, you will get the same percent elongation on both (for arguments sake, say 10%). So, the 1 foot belt will now be 1.1 feet and the 100 foot belt will be 101 feet under tension. They stretched different absolute amounts, but the same percent wise.

Klim

If we're going to get serious, then I suppose we ought to be clear about the three phases or zones (or something-or-other - I don't know the technical terms) for applying tension to a semi-elastic thing like a seat-belt. The first phase is when the tension is below the yield point. No stretching occurs. The second phase is when you do succeed in stretching the material, but you're still within the elastic zone. The stretching that occurs in this phase is pretty much like stretching any other elastic material, such as a rubber band or car's coil spring. And it's linear, so you can describe the stretch as a percent of original length. Note, however, that the elastic zone for a racing seat-belt is rather thin unless it has one of those gizmos like a Schroth Rallye belt has. Finally, you've exceeded the ability of the material to stretch elastically and you start stretching it permanently. This goes on for a little while (with a much shallower slope than the elastic phase - as in: more tension is needed for a given amount of stretch) and it's often non-linear for reasons I don't understand at all. Then, finally, the belt snaps as you surpass the breaking tension.

This is what I mean by it being non-linear. The function relating tension to stretch is, at first, flat, then linear, then shallower and non-linear, and finally infinite (when the belt breaks).

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Iowa999
If we're going to get serious, then I suppose we ought to be clear about the three phases or zones (or something-or-other - I don't know the technical terms) for applying tension to a semi-elastic thing like a seat-belt. The first phase is when the tension is below the yield point. No stretching occurs. The second phase is when you do succeed in stretching the material, but you're still within the elastic zone. The stretching that occurs in this phase is pretty much like stretching any other elastic material, such as a rubber band or car's coil spring. And it's linear, so you can describe the stretch as a percent of original length. Note, however, that the elastic zone for a racing seat-belt is rather thin unless it has one of those gizmos like a Schroth Rallye belt has. Finally, you've exceeded the ability of the material to stretch elastically and you start stretching it permanently. This goes on for a little while (with a much shallower slope than the elastic phase - as in: more tension is needed for a given amount of stretch) and it's often non-linear for reasons I don't understand at all. Then, finally, the belt snaps as you surpass the breaking tension.

This is what I mean by it being non-linear. The function relating tension to stretch is, at first, flat, then linear, then shallower and non-linear, and finally infinite (when the belt breaks).

Kinda, sorta....you are describing the properties of things like steel, aluminum, etc. It starts out 'elastic' ( meaning returns to original shape when load is removed); stretching occurs but the material returns to its original shape. The yield point is where the material starts to bend in-elastically....becomes plastic and is deformed when the load is released.

For belts, this is not really the case. Presumably, they return to their original shape regardless, unless they break. But the idea of the rate of enlongation does change very markedly with load changes; that is the non-linearity.

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mulik52
I don't think this is accurate. You will get the same percent elongation per a given load, ir-regarding of total length. So, if you take a belt which is 100 feet and a belt which is 1 foot, and apply the same load (say 1000lb), if the cross section area of the belts is the same, you will get the same percent elongation on both (for arguments sake, say 10%). So, the 1 foot belt will now be 1.1 feet and the 100 foot belt will be 101 feet under tension. They stretched different absolute amounts, but the same percent wise.

Klim

Well I guess I am not doing a very good job or thinking of it wrong. I see your point: the load per length seems like it would be constant, since the sections are all in series, not in parallel. This is going to bug me all night!