'What about building 7'?

[Oystein]

It's not just truthers being educated.

Posters such as pgimeno, LSSBB, Jay Utah and others have clarified to many of us the issues and supplies us with reasonable explanations to these truther talking points making us laypeople less susceptible to believing nonsense.

*seconded*

I'd like to add that I am occasionally learning and understanding bits from things the truthers post. Also, errors committed on boths sides are sometimes enlightning.

 

[gerrycan]

You mean such as how CTE actually varies with temperature for most materials, including steel, over broad temperature ranges such as 0 C to 600 C?

You even typed that and never noticed the error in grizzly's numbers

 

[Grizzly Bear]

What co-efficient did you use?

Think i gave that to you when we talked about this previously. Check the chain of posts. The 3 figures were to accomodate different possibilities since the list used for the coefficients doesnt specifically reference building grade steel. I will look later, but the effort was to show that the figures fell within a margin of error to NISTS, NOT to prove then right or wrong given the limitations of simplified models

 

[JayUtah]

You even typed that and never noticed the error in grizzly's numbers

The point I was trying to make did not require me to fact-check Grizzly's post. Is there some reason you're beating this horse?

 

[DGM]

The point I was trying to make did not require me to fact-check Grizzly's post. Is there some reason you're beating this horse?

He has no more in the stable.

 

[pgimeno]

So quantify it then.

Me? You're the one claiming the report is in error based on a flawed premise. Fix your premise.

 

[gerrycan]

Think i gave that to you when we talked about this previously. Check the chain of posts. The 3 figures were to accomodate different possibilities since the list used for the coefficients doesnt specifically reference building grade steel. I will look later, but the effort was to show that the figures fell within a margin of error to NISTS, NOT to prove then right or wrong given the limitations of simplified models

No, the 3 figures line up exactly with the 3 points that you used in the AISC graph, but what your figures show is that even the NIST 5.5" estimate for expansion was ambitious to say the least.
It wasn't until I worked back to what your 3 average coefficients of thermal expansion would be, and then looked at the graph that I realised just how exactly they lined up.
If you didn't take those 3 numbers from that graph, I want you to private message me some lottery numbers.

 

[JayUtah]

The odd personalization of the debate is getting tedious. Only in this bizarre context could another poster post an example, the discussion of which would devolve into trying to call me out. Twice.

 

[gerrycan]

Me? You're the one claiming the report is in error based on a flawed premise. Fix your premise.

Yes, and as you are claiming that the column shift, which NIST make fleeting reference to, added to the displacement, so quantify it. And as for premises, there is enough redundancy there.

 

[DGM]

I'm wondering what the code recommendations would be to prevent controlled demolition of an occupied building. Constant structure monitoring to insure no one has rigged it while no one was watching? Indestructible buildings? This is about safety after all.

 

[Grizzly Bear]

No, the 3 figures line up exactly with the 3 points that you used in the AISC graph, but what your figures show is that even the NIST 5.5" estimate for expansion was ambitious to say the least.
It wasn't until I worked back to what your 3 average coefficients of thermal expansion would be, and then looked at the graph that I realised just how exactly they lined up.
If you didn't take those 3 numbers from that graph, I want you to private message me some lottery numbers.

Good grief man... you didnt reverse engineer the values... i linked you to the source AND told you what my. Calcs used. I also limited the scope applicability. If you want to take those values and tell me im wrong because you're reading my intent the same way TZ et al read Bazants limiting models, then you're taking my comment waaaay too far
http://www.internationalskeptics.com/forums/showpost.php?p=9953540&postcount=997

 

[beachnut]

Yes, and as you are claiming that the column shift, which NIST make fleeting reference to, added to the displacement, so quantify it. And as for premises, there is enough redundancy there.

Where is your theory? You can't debunk other probable causes and have your theory win. You need evidence. Why can't you support or present your theory based on CD, and inside job?

http://911blogger.com/news/2014-03-07/being-smeared-911-truther-msm#comment-260973

This explains why you bash NIST, and your lack of knowledge explains why you fail to make a point bashing NIST.
But why fail to present your CD theory, and all your overwhelming evidence for CD and the inside job which in your fantasy brought down WTC 7. The "new approach" propaganda tactic failed, what will you do now?

How will you refute effects from fire caused the collapse of WTC 7? You can't; so you are stuck with your NISTian campaign based on nothing. I knew on 911 it was fire, here you are stuck trying to refute NIST, and failing at your own "new approach".

What is your theory, how does it explain the free-fall, no sounds of explosives, and the fact the interior began falling 12 seconds before the roof-line?

Why can't you explain your theory?

 

[LSSBB]

Yes, and as you are claiming that the column shift, which NIST make fleeting reference to, added to the displacement, so quantify it. And as for premises, there is enough redundancy there.

No, you need to accommodate the possible variations in your 'estimate'. You are currently cherry picking one column position based on the point you want to argue.

 

[gerrycan]

Good grief man... you didnt reverse engineer the values... i linked you to the source AND told you what my. Calcs used. I also limited the scope applicability. If you want to take those values and tell me im wrong because you're reading my intent the same way TZ et al read Bazants limiting models, then you're taking my comment waaaay too far
http://www.internationalskeptics.com/forums/showpost.php?p=9953540&postcount=997

Fair enough, but to let you see what I mean about how closely your figures line up with the graph......
For linear expansion, your 3 figures are (m) 0.09271, 0.12192 and 0.161798.
Multiplying the initial length (16m) by change in temp (579C) gives 9264.
dividing your earlier 3 figures by this gives average coefficients of 1.000755613126079e-5, 1.316062176165803e-5, and 1.746524179620035e-5.

To look at the AISC graph in NISTs report and take 21C, 300C and 600C as low, medium and high points to get coefficients for would give very roughly >1.1e-5, >1.4e-5 and >1.75e-5.

 

[gerrycan]

No, you need to accommodate the possible variations in your 'estimate'. You are currently cherry picking one column position based on the point you want to argue.

Fair enough. But we should also therefor include the failure of K3004 connection at C38. There goes another inch right there.

 

[DGM]

Fair enough, but to let you see what I mean about how closely your figures line up with the graph......
For linear expansion, your 3 figures are (m) 0.09271, 0.12192 and 0.161798.
Multiplying the initial length (16m) by change in temp (579C) gives 9264.
dividing your earlier 3 figures by this gives average coefficients of 1.000755613126079e-5, 1.316062176165803e-5, and 1.746524179620035e-5.

To look at the AISC graph in NISTs report and take 21C, 300C and 600C as low, medium and high points to get coefficients for would give very roughly >1.1e-5, >1.4e-5 and >1.75e-5.

I'd really love to know what point you're trying to make here.

 

[Oystein]

Fair enough. But we should also therefor include the failure of K3004 connection at C38. There goes another inch right there.

Being no more than an intern in this discussion, watching the pros battle it out, I may be out on a limb now, but I'll say it anyway:

This is getting most silly!

On several floors, many beams, girders, columns, concrete slabs and what else have your were subject to a history of heating and cooling caused by wandering fires, right?
So hundreds of elements in that 16-story assembly that NIST considered were subject to all sorts of heat-induced contortions - expanding, contracting, bending, torquing, ... right?
Each node thus was likely to move some distances up, down, N, E, W, S by different distances at different times - right?
And those distances would not only depend on the heat-induced deformation of the elements that come together at that node, but also on the displacememts of all the neighboring nodes, which in turn are affected by displacements of nodes that they link to - right?
NIST ran an FEA with ANSYS, which resulted in such displacements of nodes - right?
Their model produced as implicit and explicit results displacements of every node at many points in time, right?
And quite generally, we do not know the values of almost all such displacements, right?
We know them neither in the NIST model, nor in the reality of the burning building, right?

So how can you pick out one single element, claim a single value of displacement or non-displacement or whatever that 1 inch is that you are talking about, and try to make us believe that somehow this particular inch makes or breaks the overall outcome of "fire induced floor failure at col. 79"? This appears to me to be exceedingly silly!

 

[gerrycan]

I'd really love to know what point you're trying to make here.

I am illustrating that Grizzly took the CTE of steel for 3 separate temperatures over a range and then reapplied those 3 coefficients separately over the entire range each time.
He should have taken those 3 values and applied them to the temperature curve and arrived at one figure for expansion, not 3.
His post gave the impression that 6.37" of linear expansion is possible in a 53ft beam at 600C from room temp, and it just isn't.

 

[DGM]

So how can you pick out one single element, claim a single value of displacement or non-displacement or whatever that 1 inch is that you are talking about, and try to make us believe that somehow this particular inch makes or breaks the overall outcome of "fire induced floor failure at col. 79"? This appears to me to be exceedingly silly!

You need to stop looking at the big picture, it clouds the small detail.

 

[DGM]

I am illustrating that Grizzly took the CTE of steel for 3 separate temperatures over a range and then reapplied those 3 coefficients separately over the entire range each time.
He should have taken those 3 values and applied them to the temperature curve and arrived at one figure for expansion, not 3.
His post gave the impression that 6.37" of linear expansion is possible in a 53ft beam at 600C from room temp, and it just isn't.

Is this one beams linear expansion the only aspect that needs to be considered in the displacement? If so, please qualify.