KreeL,
First off, where did you get your degree? What specialty? How many years experience? (For me: Cornell U, BS Mech Engr., 34+ years)
Bazant proves nothing. His one-dimensional model is a fraud. He doesn't explain where he gets his data. Even NIST contradicts him all over the place. He is a government shill.
"... one dimensional model is a fraud..."?? Please enlighten me. I've only got about 15 years experience in FEA modeling, and I'm a bit confused. I principally use my own seat of a product called Cosmos. But every program I've ever used has one dimensional models (aka, "elements") for long, slender 3 dimensional objects. You know, objects like the Twin Towers.
Are all of those programs "shill programs", too.
Please, KreeL. Enlighten me. Why do they provide these fraudulent "models"??
The case of the debunking of Bazant has been presented dozens of times. If you haven't read the peer reviews, then you should. All of his papers failed, all three of his theories (so far, he's probably coming up with another one later this year) have failed.
Get up to speed, and report back.
Again, I must have missed it. Please point me to these debunkings. Please explain to me (I'll struggle to follow along, I promise) EXACTLY how his papers "failed".
Just out of curiosity, did any of those debunkers teach at Northwestern? MIT? Stanford?
Did they belong to the National Academy of Engineering?
Bazant states (with zero evidence) that the cores got red hot (800C) for a sustained period of time (he doesn't say how long). Please help him out with this simple statement. Does NIST say all the core columns were a sustained 800C? How does Bazant know this?
edited to add -- he must be psychic...OR he's trying to make his model seem 'plausible' (faithbased, of course).
I was happy to see his temp predictions. They matched the ones that I made about 5 years ago. Why don't you tell me the criteria by which you came to YOUR conclusions about those temps. Your OWN work, please. Not NIST's. Then I'll tell you how I came to my conclusions.
BTW, do you understand the difference between "some columns got up to 800°C" and "all the columns were a sustained 800°C"??
BTW, I am sure that, being the talented engineer that you clearly are, you're aware that Dr. Bazant has shown, uh excuse me, has PROVEN that the fatal damage to the columns in the towers could have happened at temps as low as 250 - 300°C.
Of COURSE you are.
The conflagration, caused by the aircraft fuel spilled into the structure, causes the steel of the columns to be exposed to sustained temperatures apparently exceeding 800oC… ( Bazant and Zhou, 2002, p. 2. )
You do realize that "exposed to temperatures of" is not the same as "achieve temperatures of". Office fires burn at 1200 - 1300°C. Beams are "exposed to" those temperatures. Without sprinklers or insulation, an enormous body of engineering data proves that, in large fires, the beams will quickly heat up to temps in the 800 - 1000°C range.
But here we note from the recent NIST report that: “The initial jet fuel fires themselves lasted at most a few minutes” and office material fires would burn out within about 20 minutes in a given location. (NIST, 2005; p. 179, emphasis added.) Certainly jet fuel burning was not enough to raise steel to sustained temperatures above 800oC.
Of course you realize that "about 20 minutes" is an estimate, and "a given location" is rather nebulous.
BTW, how do you explain the 18 - 20 HOUR fire in the Windsor Towers fire if fires "burn out in 20 minutes in a given location"? Did they keep importing new "locations"? Did they have 60 different locations? It sure looked to me like a whole bunch of those locations were all burning simultaneously for awile.
Perhaps you could also give us YOUR assessment as to how the WTC fire differed from typical office fires.
Once more than half of the columns in the critical floor.. suffer buckling (stage 3), the weight of the upper part of the structure above this floor can no longer be supported, and so the upper part starts falling down onto the lower part below…”( Bazant and Zhou, 2002, p. 2. )
Bazant & Zhou do not explain how “more than half of the columns in the critical floor suffer buckling” at the same time to precipitate the complete and nearly symmetrical collapse observed. There were 47 huge steel core columns in each Tower, and 24 such support columns in WTC 7 (NIST 2005; NISTb, 2005).
Of course Bazant & Zhou didn't explain that. Do you NOT understand how that happened? With your engineering expertise?
I am shocked, KreeL. Shocked.
Allow me to provide you with a hint: NASA never explained how all those millions of pieces of the Shuttle Challenger knew to "disassemble at the same moment" either.
Think about it...
They do NOT explain how steel-column temperatures above 800oC were achieved near-simultaneously due to burning office materials.
They didn't.
You don't get it, KreeL. The temperature did not cause the failure. A loss of geometry in the supports and the loads caused the failures.
Physical damage caused the loads to shift, to become asymmetric, increasing dramatically in some areas. But not to immediate failure. The fires warmed the steel which allowed them to creep. Creep allowed the loads to shift from purely compressive or shear to bending.
Damage -> Asymmetric Loading -> small bending loads -> Fires -> Creep -> more tilting of the top & sagging of the floors -> higher bending loads -> higher stress -> higher creep -> higher tilting & sagging -> highest bending loads -> highest stress -> unsustainable tilting & sagging -> BUCKLING & FRACTURE...!
Lots of parts failed before the collapse began. In each case, some other component still had the ability to take up the lost load. But that margin was shrinking & shrinking. Finally, there was no more margin. Then one more piece failed, and everything else failed immediately after it. Because there was nothing that could take up the lost strength of the one failed piece.
NOW do you see how they all failed "simultaneously"?
NIST notes that office materials in an area burn for about 15-20 minutes, then are consumed away (NIST, 2005, pp. 117, 179). This is evidently not long enough to raise steel column temperatures above 800oC as required in the Bazant & Zhou model, given the enormous heat sinks of the structures.
Wrong. Review the Cardington Fire studies & you'll see that the steel temps can rise VERY rapidly. 20 minutes is more than enough. Especially for long thin beams. Let me ask you a question: If you have a column on the 93rd floor that is being heated by fire, but the 92nd & 94th floor parts of the same column are ALSO being heated by fire, where do you think the heat input on the 93rd floor are supposed to flow TO??
And to have three buildings completely collapse due to this unlikely mechanism on the same day strains credulity.
It strains credulity. And is wrong.
Two buildings had planes fly into them. Two buildings collapsed by this mechanism.
WTC7 collapsed due to a COMPLETELY DIFFERENT mechanism.
But, gee, you've only been told this about 50 times, I suppose...
Moreover, the Final NIST report on the Towers admits:
Of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250ºC… Only two core column specimens had sufficient paint remaining to make such an analysis, and their temperatures did not reach 250 ºC. … Using metallographic analysis, NIST determined that there was no evidence that any of the samples had reached temperatures above 600 ºC. (NIST, 2005, pp. 176-177; emphasis added.)
Again, you give me YOUR thermal analysis on the core & peripheral columns. Then I'll show you mine.
-- simple fact fuzzups between NIST and Bazant as researched by David Ray Griffin
As researched by the religious studies guy...
Blinded by your faith once again.
Impossible to refute the facts, huh beachnut? So which one really lied? Bazant, or NIST?
No faith.
Engineering.
I'm waiting to see yours.
Neither Bazant not NIST lied. YOUR lack of understanding does not constitute THEIR lies.
Let's see if you can match their honesty.
tom