Analysis of Bazant & Zhou (2002)
- Thread starter bofors
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Hokulele
Deleterious Slab of Damnation
Is this a discussion, or simply a spam of Hoffman's work?
KoihimeNakamura
Creativity Murderer
Because it is commmonly understood (for some value of common) that weakened steal cannot providet he same strength. And steel heated to a certain temperature is weakened (IIRC, around 300C+).
I'll defer to someone who has experience in this, but with your track record so far...
The probablity of an event occuring that has occured is 1.
bofors
Muse
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Page 1, Paragraph 2:
In stage 1 Fig. 1 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 800°C.
The heating is probably accelerated by a loss of the protective
thermal insulation of steel during the initial blast.
Point 10 Bazant & Zhou claim their model is for "sustained temperatures apparently exceeding 800°C", however, actual tests of uninsulated steel show temperatures never exceed 360°C. Furthermore, NIST's report indicates by paint analysis that only three out of sixteen perimeter columns examined reached temperatures above 250°C and neither two core columns examined reached temperatures above 250°C. Moreover, NIST metallography showed no evidence of temperature higher than 600°C.
http://911research.wtc7.net/essays/nist/index.html#exaggeration
Ref. NIST Report, pages 90/140.
Point 11 Without providing any quantitative basis, model or even an estimate, Bazant & Zhou claim a significant portion of steel-insulation was dislocated.
Point 12 Bazant & Zhou fail to provide any consideration of the amount of air flow that would have been required for any fire to reach 800°C in 56 minutes.
http://www.opednews.com/articles/opedne_joseph_s_070522_oh_yeah_2c_here_s_anot.htm
In stage 1 Fig. 1 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 800°C.
The heating is probably accelerated by a loss of the protective
thermal insulation of steel during the initial blast.
Point 10 Bazant & Zhou claim their model is for "sustained temperatures apparently exceeding 800°C", however, actual tests of uninsulated steel show temperatures never exceed 360°C. Furthermore, NIST's report indicates by paint analysis that only three out of sixteen perimeter columns examined reached temperatures above 250°C and neither two core columns examined reached temperatures above 250°C. Moreover, NIST metallography showed no evidence of temperature higher than 600°C.
http://911research.wtc7.net/essays/nist/index.html#exaggeration
Ref. NIST Report, pages 90/140.
Point 11 Without providing any quantitative basis, model or even an estimate, Bazant & Zhou claim a significant portion of steel-insulation was dislocated.
Point 12 Bazant & Zhou fail to provide any consideration of the amount of air flow that would have been required for any fire to reach 800°C in 56 minutes.
http://www.opednews.com/articles/opedne_joseph_s_070522_oh_yeah_2c_here_s_anot.htm
funk de fino
Dreaming of unicorns
This is no engineer, it is just a spammer at work
Ignore the troll please
Ignore the troll please
You do understand the insulation on the core was wall board, and under the floors was spray on, very fragile.
Think the fire proofing was disloged.
Oops, look like you made an error. It looks like the impact dislodged tons of insulation and columns too. A reminder, the fire insulation is wall board. Yes the stuff my roommate in college punch holes though with his fist. Bet you forgot to see what the insulation was made of.
Visually debunked! See?
Last edited:
KoihimeNakamura
Creativity Murderer
I think he's going to post the entire criticism first without reading the replies. Dunno -why- though.
KoihimeNakamura
Creativity Murderer
They probably also didn't test columns directly hit by the fires, either, as others have commented. (And 300+ is when they lose structural strength..)
Plane. Hitting. Building.
[/quote]
Urk. I dunno, THE FACT THEY HAVE BROKEN WINDOWS? EXPOSED TO THE AIR? OFFICE... *sigh*
I have a novel idea. How about responding to the rebuttals?
boloboffin
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If all you're going to do is post these points, bofors, why are you posting them three at a time?
bofors
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Page 1, Paragraph 2:
The vertical impact of the mass of the upper part onto the lower part (stage 4) applies enormous vertical dynamic load on the underlying structure, far exceeding its load capacity, even though it is not heated. This causes failure of an underlying multifloor segment of the tower (stage 4), in which the failure of the connections of the floor-carrying trusses to the columns is either accompanied or quickly followed by buckling of the core columns and overall buckling of the framed tube, with the buckles probably spanning the height of many floors (stage 5), at right, and the upper part possibly getting wedged inside an emptied lower part of the framed tube (stage 5), at left. The buckling is initially plastic but quickly leads to fracture in the plastic hinges.
Point 13 Bazant & Zhou claim failure proceeds by many floors at time, however, the demolition waves clearly visible in the "collapse" video indicates some other process is under way.
Point 14 Bazant & Zhou claim the failure mechanism is characterized by buckling that "probably span[] the height of many floors", yet no such multi-story buckles were found in the debris. Moreover, the debris columns are largely buckle-free.
Point 15 Despite stating that buckling quickly leads to fracture, the authors fails consider any role that fracture might play in the "collapse" mechanism such as leading to the building-top tipping over.
Point 16 Bazant & Zhou fail to even consider why multi-column perimeter sections can be seen peeling off the sides of tower during "collapse".
Point 17 Bazant & Zhou fail to even consider how steel sections of up to 10 tons are ejected during the "collapse" and lodged in adjacent buildings.
Point 18 Bazant & Zhou fail to even consider how all of the concrete is pulverized in dust, nor the energy required to do so.
http://911research.wtc7.net/papers/dustvolume/index.html
Point 19 Bazant & Zhou fail any details of the mechanism of the clearly systematic floor by floor failure in terms of perimeter columns, core columns and trusses. Exactly how these parts interact with each other is left unconsidered.
The vertical impact of the mass of the upper part onto the lower part (stage 4) applies enormous vertical dynamic load on the underlying structure, far exceeding its load capacity, even though it is not heated. This causes failure of an underlying multifloor segment of the tower (stage 4), in which the failure of the connections of the floor-carrying trusses to the columns is either accompanied or quickly followed by buckling of the core columns and overall buckling of the framed tube, with the buckles probably spanning the height of many floors (stage 5), at right, and the upper part possibly getting wedged inside an emptied lower part of the framed tube (stage 5), at left. The buckling is initially plastic but quickly leads to fracture in the plastic hinges.
Point 13 Bazant & Zhou claim failure proceeds by many floors at time, however, the demolition waves clearly visible in the "collapse" video indicates some other process is under way.
Point 14 Bazant & Zhou claim the failure mechanism is characterized by buckling that "probably span[] the height of many floors", yet no such multi-story buckles were found in the debris. Moreover, the debris columns are largely buckle-free.
Point 15 Despite stating that buckling quickly leads to fracture, the authors fails consider any role that fracture might play in the "collapse" mechanism such as leading to the building-top tipping over.
Point 16 Bazant & Zhou fail to even consider why multi-column perimeter sections can be seen peeling off the sides of tower during "collapse".
Point 17 Bazant & Zhou fail to even consider how steel sections of up to 10 tons are ejected during the "collapse" and lodged in adjacent buildings.
Point 18 Bazant & Zhou fail to even consider how all of the concrete is pulverized in dust, nor the energy required to do so.
http://911research.wtc7.net/papers/dustvolume/index.html
Point 19 Bazant & Zhou fail any details of the mechanism of the clearly systematic floor by floor failure in terms of perimeter columns, core columns and trusses. Exactly how these parts interact with each other is left unconsidered.
Hi Bofors:
I have talked (on the phone) to Prof. Bazant about his famous WTC paper. To be honest I believe he completed it so quickly because he is a fast and prolific researcher and he wanted to be the first to publish something on the topic. Take a look at his career output .... he has over 400 papers and half a dozen books, one of which is over 1000 pages if I remember correctly!
As for your 19 points, I think you are incorrect about NIST's tests of uninsulated steel showing that temperatures never exceed 360°C. Check out NCSTAR 1-5B and 1-5C.
I have talked (on the phone) to Prof. Bazant about his famous WTC paper. To be honest I believe he completed it so quickly because he is a fast and prolific researcher and he wanted to be the first to publish something on the topic. Take a look at his career output .... he has over 400 papers and half a dozen books, one of which is over 1000 pages if I remember correctly!
As for your 19 points, I think you are incorrect about NIST's tests of uninsulated steel showing that temperatures never exceed 360°C. Check out NCSTAR 1-5B and 1-5C.
RAZEtheFLAG
Banned
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The Bazant report is what got NIST in trouble. They adopted his thrown together quickly theory and ran with it. Unfortunately as they did their physical fire testing to work backwards to support this theory they couldn't reach the results to support it. That's why for one thing they blame building content fire more then jet fuel. They then went to the computer and had to keep tweaking the numbers so they stopped at initiation and bailed out.
DGM
Skeptic not Atheist
You are an engineer? Please show me where Blazant got it wrong.
Totovader
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To everyone asking why he's only posting a few points at a time and unable to answer any rebuttals: he's doing that because he's posting as he's reading. This means he has no valuable insight into the paper has he has not researched the topic or investigated any of his suspicions, he's just repeating what Hoffman has said and mashing up the words into his own in order to avoid obvious plagiarism. He will be entirely incapable of supporting these claims or backing them up without echoing Hoffman and has already contradicted himself on his points.
If he can't answer the rebuttals now- he won't be able to, tomorrow: he's made the mistake of assuming that Hoffman has done the research, and has not done any investigation whatsoever to confirm or deny that. This reading he's doing aloud would have been a step in the right direction if he had not already abandoned critical thinking.
If he can't answer the rebuttals now- he won't be able to, tomorrow: he's made the mistake of assuming that Hoffman has done the research, and has not done any investigation whatsoever to confirm or deny that. This reading he's doing aloud would have been a step in the right direction if he had not already abandoned critical thinking.
technoextreme
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It's a technical paper. Hence they would be laughed at if they wrote it to baby people like what you are suggesting.
So if all the point he made are Hoffman's (please tell me if this is so), then Bofors is a new addition to my ignore list. He has been given ample opportunity to actually provide theory and critiques of his own, but apparently wants to be lazy and simply rehash someone elses work.
Not very admirable for a scientist.
TAM
Not very admirable for a scientist.
TAM
Alareth
Philosopher
All he did in the other threads was parrot Hoffman, why should we expect anything different from him now?
ElMondoHummus
0.25 short of being half-witted
Yeah, true. Everyone, he's finally providing specific arguments instead of promises of such. Let's let him make his points, then we can analyze and critique them.
Hey, man, it doesn't matter how he makes his points. He's finally making them. So we get to tackle them 3 or so at a time instead of in one long ball of mush like some others. Big deal. Let him do it this way; doesn't change the addressibility of his points. In fact, it sort of makes things more readable, and is much less the sort of "spaghetti thinking and writing" that most fantasists put down.
Let's let him do it this way. The arguments will still stand or fall on their own merits.
So if all the point he made are Hoffman's (please tell me if this is so), then Bofors is a new addition to my ignore list. He has been given ample opportunity to actually provide theory and critiques of his own, but apparently wants to be lazy and simply rehash someone elses work.
Not very admirable for a scientist.
TAM
Yeah, it looks like it to me too. That should make it easier to address: "See here (link previous JREF thread)...".
You know, I get the "Groundhog Day" feeling too, just as bad as everyone else here. But the appearance of folks like Diagoras, 16.5, Buka001 and others make me realize the importance of addressing the charges when they're made, even if that involves nothing more than "hey, we already talked this to death; do a search for (fill-in-the-blank)".
Don't get me wrong, TAM, I'm not saying you shouldn't have him on ignore or that I disagree with you. I'm just reiterating the point that some of us here - not you specifically; I'm just using your post as a launching board, not singling you out - should remember to put something out there for the lurkers and newbies to be able to latch on to. We never know when they're around.
Let's let bofors do his thing. Then for those of us who want to take the burden this time around, let's keep doing what we always do: Critique and demonstrate where the errors are.