Moderated Steel structures cannot globally collapse due to gravity alone

Christopher7 said:
Perhaps you missed this:
Bazant admits that he has a one dimensional model that is not consistent with the actual collapse.

Bazant did NOT explain how the towers collapsed.

He has a theory about how they might have collapsed - if all his assumptions are correct.
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As I've stated... for the umpteenth time... his model was exceptionally biased to include all of the most optimistic conditions for the collapse arrest. Of course it doesn't match the actual collapse, the actual collapse had nothing nearly ideal for that... If you refuse to acknowledge this, or still don't understand that... then tough luck, I'm not repeating myself, for better or for worst you won't acknowledge it. Big font doesn't make it any more correct.
 
Only an idiot or a parrot will squawk BAZANT! BAZANT! after being told that a 8 year old paper is no longer considered to be a good explanation of the event, but that a really good explanation was provided by NIST in a freely-accessible PDF.
 
Dave,

Well, whatcha know.

I just did a quick calculation, based on a single beam, 444" long, 13" thick x 14" wide on the outside, 12.5" thick x 13.5" wide cut-out interior, yield strength 70 Ksi, cantilever.

The force you can put on it and keep the outer fiber stresses below Sy is about 1,850 lbs with a deflection of 5.3". This gives about 4,900 in-lb potential energy.

Converting this entirely into linear velocity gives about 83 ft/sec = 56 mph.

A quick check of the rotational energy (0.5 Ixx omega^2) shows the rotational energy for one of these (almost hollow) box beams to be a trivial percent of the linear energy. So, figure it drops the linear velocity to about 54 mph.

Note that I figured this for a cantilevered beam, which stores only half as much energy as a beam that is bent into a uniform arc throughout its length. Twice as much energy gives you 41% more velocity, or 76 mph. Not bad.

Bill, what this calc does show is that, contrary to what you were "certain of", the box beams can take quite a bit of deflection (over 5") before they start to take a set, and substantially more than this before they are in danger of kinking. And they can store an enormous amount of energy in them in the process.

As expected, until one runs the numbers, you don't know what you're gonna get. And you, bill, have precisely ZERO "feel" for any of this.

You have simply your wishful thinking, based on your foregone conclusions.

tk
 
Grizzly Bear said:
As I've stated... for the umpteenth time... his model was exceptionally biased to include all of the most optimistic conditions for the collapse arrest.
Click to expand...
That is his opinion.

Of course it doesn't match the actual collapse, the actual collapse had nothing nearly ideal for that
Click to expand...
Perhaps you missed this part again:
"to answer this question fully, a three-dimensional analysis would be required."
 
Christopher7 said:
That is his opinion.

Perhaps you missed this part again:
"to answer this question fully, a three-dimensional analysis would be required."
Click to expand...
You are not using your engineer hat and you have failed to grasp the model; please stop spewing delusions.

What does one dimension mean? Did Bazant call his model one-dimensional? What does that mean? Did someone use that term and you liked it?

Explain in engineering terms what one-dimensional modeling means, please? Use a piece of one-dimensional paper please.
 
BenBurch said:
Only an idiot or a parrot will squawk BAZANT! BAZANT! after being told that a 8 year old paper is no longer considered to be a good explanation of the event,
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We agree that this paper written the day after the towers fell is not a good explanation of the event but the author put out another paper in 2007 and another in 2008. They all expand on the one written the day after the towers fell.
In the end he admits that:
"to answer this question fully, a three-dimensional analysis would be required."

but that a really good explanation was provided by NIST in a freely-accessible PDF.
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Really?
URL please, I would like to see it.

Have you seen this:

NIST reply to stj911truth
http://www.911proof.com/NIST.pdf

pg 3 NIST has stated that it did not analyze the collapse of the towers.

PG 4
We are unable to provide a full explanation of the total collapse.
NIST’s analysis was carried to the point of collapse initiation.
 
JimBenArm said:
Silly people! Carbohydrates can't hurt steel. Why, I just smacked an I-beam with a turkey sandwich (Perdue turkey, BTW, purchased at Purdue) and it had no effect on the beam at all!

Anyone have a mop?
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:confused: Oh, great, now I got this image in my head of JBA slapping a five-buck footlong against an I-beam and yelling incoherencies like "Freunlaven!!" over and over again while waiting for the cops to show.

Thanks a lot, Jim! :curse
 
beachnut said:
What does one dimension mean? Did Bazant call his model one-dimensional?
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Yes

The high tilt seen on the South Tower top (about 25_ after 4 seconds of fall, NIST 2005) would call for a three-dimensional model of progressive collapse. Why does the one dimensional model give nonetheless a reasonably good match? Probably because the crushing front of compacted debris tends to develop a flat front once it becomes thick enough (Fig. 6e). However, to answer this question fully, a three-dimensional analysis would be required.
 
ElMondoHummus said:
:confused: Oh, great, now I got this image in my head of JBA slapping a five-buck footlong against an I-beam and yelling incoherencies like "Freunlaven!!" over and over again while waiting for the cops to show.

Thanks a lot, Jim! :curse
Click to expand...

Man, thankfully I wasn't thinking anything like that....til now!

Thanks a lot, El! :curse
 
Christopher7 said:
Yes

The high tilt seen on the South Tower top (about 25_ after 4 seconds of fall, NIST 2005) would call for a three-dimensional model of progressive collapse. Why does the one dimensional model give nonetheless a reasonably good match? Probably because the crushing front of compacted debris tends to develop a flat front once it becomes thick enough (Fig. 6e). However, to answer this question fully, a three-dimensional analysis would be required.
Click to expand...

So what's your competing theory? Where is your paper? It will need to be every bit as detailed and scientifically sound as Bazant's paper, of course.

To every expert I have asked Bazant's 'opinion' IS scientifically sound. I therefore must consider it scientifically sound until another theory becomes widely accepted in the scientific community. Do you have one of those?
 
Christopher7 said:
Yes

The high tilt seen on the South Tower top (about 25_ after 4 seconds of fall, NIST 2005) would call for a three-dimensional model of progressive collapse. Why does the one dimensional model give nonetheless a reasonably good match? Probably because the crushing front of compacted debris tends to develop a flat front once it becomes thick enough (Fig. 6e). However, to answer this question fully, a three-dimensional analysis would be required.
Click to expand...
Explain in engineering terms what one-dimensional modeling means, please? Use a piece of one-dimensional paper please.

I wanted you to explain what he is talking about and you failed to explain. Good job.

Explain why the model that matches the timing of the WTC collapse is called one-dimensional. It must be simple for you as you prepare to win the Pulitzer Prize for exposing the vast conspiracy of CD at the WTC. Do it.
 
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