Mechanics of the WTC collapse:Cherepanov

[Sizzler]

Mechanics of the WTC collapse
Journal International Journal of Fracture
Publisher:Springer Netherlands
ISSN 0376-9429 (Print) 1573-2673 (Online)
Issue Volume 141, Numbers 1-2 / September, 2006
Category: Original Article
Pages 287-289
Subject Collection, Chemistry and Materials Science
SpringerLink Date, Tuesday, October 31, 2006



G. P. Cherepanov1 Contact Information
(1) Honorary Life Member, New York Academy of Sciences, 6413 SW 11B Ave, Miami, FL 33173, USA

Received: 11 July 2005 Accepted: 05 May 2006
Abstract Two theories of the WTC collapse are examined. The first one is the theory of progressive failure, and the other one is the theory of fracture waves. The collapse in the regime of progressive failure is shown to occur at an acceleration, which is several times less than the gravitational acceleration and, hence, this theory contradicts to the observed free fall. Evidently, the WTC towers were disintegrated at the very beginning of each collapse. To explain this fact an alternative model based on the theory of failure waves is proposed.

Does anyone know where I can get a full copy of this for free?

Can anyone post it if they have it?

Thanks.

[beachnut]

Mechanics of the WTC collapse
Journal International Journal of Fracture
Publisher:Springer Netherlands
ISSN 0376-9429 (Print) 1573-2673 (Online)
Issue Volume 141, Numbers 1-2 / September, 2006
Category: Original Article
Pages 287-289
Subject Collection, Chemistry and Materials Science
SpringerLink Date, Tuesday, October 31, 2006

Does anyone know where I can get a full copy of this for free?
Can anyone post it if they have it?
Thanks.
OMG, it was suppose to be a secret! Hundreds of independent investigation on 9/11! Do not tell 9/11 truth!

So you want someone to sell intellectual property for free? You have not been sued yet by RIAA yet? Research...

http://forums.randi.org/showthread.php?t=98155 thread

different paper, is it the same person?

http://www.genadycherepanov.com/OnTheWTC_PDF.pdf paper

[Sizzler]

OMG, it was suppose to be a secret! Hundreds of independent investigation on 9/11! Do not tell 9/11 truth!

So you want someone to sell intellectual property for free? You have not been sued yet by RIAA yet?

http://forums.randi.org/showthread.php?t=98155 thread

So is that a no?

[Wildy]

Enrol in a university and use their accounts that are set up for students to go to sites like that and get the paper?

Or you could just pay for membership?

Or you could just buy a copy of the journal in question.

[beachnut]

So is that a no?
No, I posted a paper! It is his paper?! I am still editing my post as we post. I was reading the paper I posted for you. I do not agree with his ideas, it is clear the failure of the WTC is related to the heated areas, I think he disagrees!. He does not seem to be a 9/11 truth idiot; yet.

Have you read it yet; it has some funny, or odd ideas. But it is a paper of his, and it seems to cover the things you posted in the OP. Have you read the paper yet? You are welcome. ( I even posted a thread, and was going to look up more stuff... but...)

[FramerDave]

So now we're supposed to do their homework for them AND buy their books?

[Sizzler]

No, I posted a paper! It is his paper?! I am still editing my post as we post. I was reading the paper I posted for you. I do not agree with his ideas, it is clear the failure of the WTC is related to the heated areas, I think he disagrees!. He does not seem to be a 9/11 truth idiot; yet.

Have you read it yet; it has some funny, or odd ideas. But it is a paper of his, and it seems to cover the things you posted in the OP. Have you read the paper yet? You are welcome. ( I even posted a thread, and was going to look up more stuff... but...)

Thank you kindly.

Reading now.

[Pardalis]

There is also the feng-shui overload theory (http://forums.randi.org/showpost.php?p=1612304&postcount=2329), if you're interested.

[Sizzler]

Another Soviet immigrant.

One more and there may be a pattern....no?

[Sizzler]

No, I posted a paper! It is his paper?! I am still editing my post as we post. I was reading the paper I posted for you. I do not agree with his ideas, it is clear the failure of the WTC is related to the heated areas, I think he disagrees!. He does not seem to be a 9/11 truth idiot; yet.

Have you read it yet; it has some funny, or odd ideas. But it is a paper of his, and it seems to cover the things you posted in the OP. Have you read the paper yet? You are welcome. ( I even posted a thread, and was going to look up more stuff... but...)

after reading it i realized it isn't the exact one from the journal.

do you have that one?

[Sizzler]

Hey look, it is a well known expert:
"Professor Cherepanov is a highly original and very profilic researcher. In both quality and volume , his contributions to Applied Mechanics have been simply phenomenal.

And he is arguing against Bazant in a peer reviewed engineering journal.

I thought these didn't exist?

“Why did you think the towers collapse?”, Larry asked his guest, a prominent
member of the September 11 Commission, on a recent Larry King show. “This is
still under investigation”, the guest answered. Evidently, the public has not, as
yet, accepted the “theory” by Bazant and Zhou (2002), see Appendix 2.
Meanwhile, the engineering community has, without any hesitation, recognized
the “theory” as correct and comprehensive. This author has felt this official
recognition on his own skin after the editors and anonymous referees of numerous
technical journals refused to publish his understanding of the collapses as
contradicting to this “theory”. The most important conclusion Bazant and Zhou
derived from their analysis was that the WTC collapse was an unavoidable
consequence of the terror act. This conclusion was necessary to both sides. To the
American government, for to make the turn to the new policy designed before.
To terrorists, as a recognition of success of their strategy and an encouragement
to start jihad around the world. Meanwhile, on the opinion of the same
engineering community, this terror act could not cause a WTC collapse.
Otherwise, all people would have been evacuated from the buildings during the
fire, and 300 firemen would not have been ordered to climb up, so that, instead of
three thousand, the fatalities would not have exceeded about one hundred people.
The collapses happened unexpectedly. My point proved below is that
Bazant&Zhou’s analysis and conclusion are wrong and that the collapse was a
result of insufficient knowledge of fracture, and especially fracture wave,
mechanics ignored both in the construction of towers and in the prediction of
what could happen after the terror act.
The “theory” has suggested the following scenario of the collapse: creep buckling
of bearing columns of the critical floor, free fall and dynamic impact of the upper
structure, and progressive, floor-by-floor, buckling failure of bearing columns of the
underlying structure. This “theory” has been unable to explain these well-known facts of
the matter:
(i) Free fall regime of all collapses;
(ii) Sound of explosion produced by each collapse;
(Sound is generated by cracking. If the cracking had continued for ten
seconds, as the “theory” asserts, a boom would have been heard, not an
explosion.)
(iii) Pulverization of the buildings collapsed .
(By the “theory” the debris after the collapse would have consisted of steel
segments of columns about two meters long, and nothing more.)

He seems to understand the politics in science quite well, and from experience.

I thought free-fall collapse was invented by the truth movement? Why is this expert endorsing lies?

Why did the peer review process not catch this bold face lie?

Could disinformation be rampant on both side of the spectrum?

Or just one?

[Gravy]

Zdenek Bazant responds to G.P. Cherepanov's critique (PDF)
(http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/Progre-RebutCherepanovCritiqueOfBazZhouWTC-06.pdf)

[Pardalis]

The NIST agrees the buildings fell at essentially free fall speeds. See their FAQ pqge.

[Sizzler]

The NIST agrees the buildings fell at essentially free fall speeds. See their FAQ pqge.

So why all the debunking about fee-fall speed?

[Pardalis]

I must admit I don't really care to read the paper, but does Cherepanov address the buckling? From passing over it quickly he doesn't seem to, witch is kind of odd since it's a non-issue:

[Pardalis]

So why all the debunking about fee-fall speed?

The truther claim is that the buildings fell faster than free fall speed, which you'll agree is completely ridiculous.

[Sizzler]

Zdenek Bazant responds to G.P. Cherepanov's critique (PDF)
(http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/Progre-RebutCherepanovCritiqueOfBazZhouWTC-06.pdf)

Thanks gravy.

This paper does show that progressive collapse has been challenged in real mainstream journals that are peer reviewed.

So not ALL the experts agree. This expert agrees that free-fall is not possible under progressive collapse. So which expert to I believe?

It also confirms that he had problems getting his paper published on the premise that it opposed Bazant's theory. He clearly states this.

[Sizzler]

The truther claim is that the buildings fell faster than free fall speed, which you'll agree is completely ridiculous.

I've never heard that from the CD-hypothesis group.

They all state either, essentially or near free-fall.

NIST confirms this statements by using the same words. However many debunking sites try to discredit this. Why?

[Pardalis]

NIST confirms this statements by using the same words. However many debunking sites try to discredit this. Why?

I just told you.

[Sizzler]

I just told you.

Find me a link (recent) from a popular CD site that states

"faster than fee-fall speeds"

If you go to debunking911.com, it attempts to debunk "free-fall" not "faster than free-fall".

[beachnut]

Thanks gravy.

This paper does show that progressive collapse has been challenged in real mainstream journals that are peer reviewed.

So not ALL the experts agree. This expert agrees that free-fall is not possible under progressive collapse. So which expert to I believe?

It also confirms that he had problems getting his paper published on the premise that it opposed Bazant's theory. He clearly states this.
No, he did not say that did he; read the paper.

What free fall crap? Who said free fall? It goes impact, fire, collapse. End of story.

Then you have 9/11 truth says no it can not fall that fast. They are wrong.

Then you have this guy who said it happen as it did for this reason; some other idea on failure mode; not sure he did not finish; he wants more money, or something. He has some reason and he says we have to study more. So?

[Sizzler]

No, he did not say that did he; read the paper.

What free fall crap? Who said free fall? It goes impact, fire, collapse. End of story.

Then you have 9/11 truth says no it can not fall that fast. They are wrong.

Then you have this guy who said it happen as it did for this reason. He has some reason and he says we have to study more. So?

Did you read the paper?

He states problems getting his theory published.

He states free-fall collapse times.

He states progressive collapse doesn't fit the evidence.

Do you really want me to quote it?

[beachnut]

Did you read the paper?
He states problems getting his theory published.
He states free-fall collapse times.
He states progressive collapse doesn't fit the evidence.
Do you really want me to quote it?
TRouble because he is nuts? His paper talks about a failure mode. He disagrees with the "simple model" of others. He thinks it was
A fracture wave, originated after tensile failure of some cold bearing columns in the critical floor, disintegrated each building for about 0.05 s and produced the sound of explosion, and steel fragments freely fell down while glass, concrete and marble fragments created dust clouds. ,,, OMG, a mysterious fracture wave destroying the building. Do you think he may have problems publishing an unknown cause for building collapse?! I would read it more but I saw the building fall many times, it was a full up model! Impact, fire, collapse. Details can be found.

Ruh-Roh, this guy is a nut case. OOPS !!! He is pure nuts! He does mention free fall in his write up about 15 times. He is a dyed in the wool pure nuts 9/11 idiot guy!
You made an outstanding rediscovery.

On the opinion of David Ray Griffin, U.S. government agents acting together with bin
Laden used the terrorists for their mission , mined beforehand two towers and the
neighboring 47- story skyscraper by explosives which were detonated in a while after
the crashes.
You can judge the nut cases by what they put in their very scientific papers! These lies and hearsay would not be in a real Journal; he must of taken out the BS political tripe to get it published.

This guy is pure nuts, next time present something real! Not NUTS

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/Progre-RebutCherepanovCritiqueOfBazZhouWTC-06.pdf

Cherepanov is a CD guy, who can not say CD. Darn! Bofors...

Free Fall; when you talk about free fall, if you do not include all of this information it is meaningless.

6. How could the WTC towers collapse in only 11 seconds (WTC 1) and 9 seconds (WTC 2)—speeds that approximate that of a ball dropped from similar height in a vacuum (with no air resistance)?

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2. These elapsed times were based on: (1) precise timing of the initiation of collapse from video evidence, and (2) ground motion (seismic) signals recorded at Palisades, N.Y., that also were precisely time-calibrated for wave transmission times from lower Manhattan (see NCSTAR 1-5A).

As documented in Section 6.14.4 of NIST NCSTAR 1, these collapse times show that:

“… the structure below the level of collapse initiation offered minimal resistance to the falling building mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that energy through energy of deformation.

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increased, further increasing the demand on the floors below, which were unable to arrest the moving mass.”

In other words, the momentum (which equals mass times velocity) of the 12 to 28 stories (WTC 1 and WTC 2, respectively) falling on the supporting structure below (which was designed to support only the static weight of the floors above and not any dynamic effects due to the downward momentum) so greatly exceeded the strength capacity of the structure below that it (the structure below) was unable to stop or even to slow the falling mass. The downward momentum felt by each successive lower floor was even larger due to the increasing mass.

From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.


I disagree with them saying this kind of figure of speech approximation, but they include paragraphs explaining! "the building section above came down essentially in free fall"

9/11 truth people says the buildings could not come down that fast (as fast as they really did on 9/11), or they spew some "faster than free fall" junk.

[Dave Rogers]

Did you read the paper?

I've read Cherepanov's papers in the International Journal of Fracture. I haven't read his Journal of Applied Physics submission, which hasn't been published, most likely because the Journal of Applied Physics rejected it.

He states problems getting his theory published.

I'm not surprised. Cherepanov's main assumptions are (1) that the collapse started from roof level, which is well known not to be true, and (2) that the collapse time of the towers was not significantly different from the freefall time of an object falling from rooftop level, which is also untrue (although its incorrectness, due in part to the truth movement, is less well known). He proceeds from this to the conclusion that the entire steel structure of the towers disintegrated in the first 0.1s of the collapse, a conclusion which is not only radically different to any known behaviour of steel but is trivially refuted by watching any collapse video, in which the lower structure of the towers can be seen to remain more or less intact until the collapse zone reaches it. Therefore, since Cherepanov's starting assumptions are incorrect and his conclusions are demonstrably wrong, the only conclusion I can draw from it is that the editorial standards of the International Journal of Fracture are worryingly poor.

He states free-fall collapse times.

He doesn't give references. He says the times come from the NIST report, so he's clearly misunderstood the NIST report. He hasn't measured the collapse times himself, just assumed them. It's not good science.

He states progressive collapse doesn't fit the evidence.

All he in fact states is that progressive collapse starting from rooftop level doesn't fit his mistaken interpretation of the evidence.

Do you really want me to quote it?

No thanks. The main things Cherepanov's papers prove are:
(1) Even peer-reviewed papers can be rubbish, and
(2) Not all the woo pedlars are in the truth movement.

Dave

[Sizzler]

TRouble because he is nuts? His paper talks about a failure mode. He disagrees with the "simple model" of others. He thinks it was ,,, OMG, a mysterious fracture wave destroying the building. Do you think he may have problems publishing an unknown cause for building collapse?! I would read it more but I saw the building fall many times, it was a full up model! Impact, fire, collapse. Details can be found.

Ruh-Roh, this guy is a nut case. OOPS !!! He is pure nuts! He does mention free fall in his write up about 15 times. He is a dyed in the wool pure nuts 9/11 idiot guy!
You made an outstanding rediscovery.


You can judge the nut cases by what they put in their very scientific papers! These lies and hearsay would not be in a real Journal; he must of taken out the BS political tripe to get it published.

This guy is pure nuts, next time present something real! Not NUTS

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/Progre-RebutCherepanovCritiqueOfBazZhouWTC-06.pdf

Cherepanov is a CD guy, who can not say CD. Darn! Bofors...

Free Fall; when you talk about free fall, if you do not include all of this information it is meaningless.


I disagree with them saying this kind of figure of speech approximation, but they include paragraphs explaining! "the building section above came down essentially in free fall"

9/11 truth people says the buildings could not come down that fast (as fast as they really did on 9/11), or they spew some "faster than free fall" junk.


simple point:

he did publish a journal article that states progressive collapse is not possible due to free fall times, debris, etc. there were 3 reasons.

yes the paper i read has a lot of political garbage. does that make him scientifically crazy?

my point remains.

progressive collapse has been challenged in the mainstream for SOME of the reasons the truth movement challenges it.

So what is with all the crazy talk?

[Sizzler]

I've read Cherepanov's papers in the International Journal of Fracture. I haven't read his Journal of Applied Physics submission, which hasn't been published, most likely because the Journal of Applied Physics rejected it.



I'm not surprised. Cherepanov's main assumptions are (1) that the collapse started from roof level, which is well known not to be true, and (2) that the collapse time of the towers was not significantly different from the freefall time of an object falling from rooftop level, which is also untrue (although its incorrectness, due in part to the truth movement, is less well known). He proceeds from this to the conclusion that the entire steel structure of the towers disintegrated in the first 0.1s of the collapse, a conclusion which is not only radically different to any known behaviour of steel but is trivially refuted by watching any collapse video, in which the lower structure of the towers can be seen to remain more or less intact until the collapse zone reaches it. Therefore, since Cherepanov's starting assumptions are incorrect and his conclusions are demonstrably wrong, the only conclusion I can draw from it is that the editorial standards of the International Journal of Fracture are worryingly poor.



He doesn't give references. He says the times come from the NIST report, so he's clearly misunderstood the NIST report. He hasn't measured the collapse times himself, just assumed them. It's not good science.



All he in fact states is that progressive collapse starting from rooftop level doesn't fit his mistaken interpretation of the evidence.



No thanks. The main things Cherepanov's papers prove are:
(1) Even peer-reviewed papers can be rubbish, and
(2) Not all the woo pedlars are in the truth movement.

Dave

totally agree with you;)

[Dave Rogers]

So what is with all the crazy talk?

Actually, I doubt Cherepanov's sanity, based on his WTC papers. He's showing the classic signs of a senior scientist who's got some interesting results in a narrow field, has mistakenly got the impression that they have some wider applications, and has then gone on from that false premise to build a completely irrational belief system. It's an occupational hazard for all of us, rooted in bitterness at not being as important as we'd like to be coupled with the loss of a sense of proportion. In Cherepanov's case, he's decided that all high-rise buildings are inherently unsafe and prone to sudden global collapse for virtually no reason, and is using the WTC collapses as a vehicle to push his beliefs. He's therefore very much a fellow-traveller of the truth movement, except that he's reasoning backwards from a completely different irrationally derived conclusion.

As for the peer review issue, I suspect that in the glass fracture community he's quite justifiably respected for his body of work, so there's a presumption in his favour coupled with a lack of peer reviewers with the appropriate experience to judge his WTC work correctly. I wouldn't expect the Journal of Applied Physics to have the same limitations.

Dave

[lozenge124]

Sizzler:

Another paper that contradicts Bazant & NIST is Charles Beck "Mathematical Models of Progressive Collapse and the Question of How Did the World Trade Centers Perish" available here:

http://arxiv.org/abs/physics/0609105

It has been submitted to ASCE J. of Engineering Mechanics and is apparently still in the peer review process (see submission history).

[Quad4_72]

I've never heard that from the CD-hypothesis group.

They all state either, essentially or near free-fall.

NIST confirms this statements by using the same words. However many debunking sites try to discredit this. Why?

Look at the debris that falls around the collapsing portion of the towers. It falls quite a bit faster than the towers did themselves. Thats why whenever a twoofer says it WAS freefall, they are simply referred to the debris.

[Dave Rogers]

It has been submitted to ASCE J. of Engineering Mechanics and is apparently still in the peer review process (see submission history).

This looks a good deal more sensible and rigorous than Cherepanov, and the lengthy peer review looks like it's mainly due to major expansion of the scope of the paper rather than problems with the methodology. It's clearly suggesting that Bazant's model is over-simplified, and seems to be consistent with the core spires. It still seems to be saying that collapse propagation is expected, and one could infer from this that explosives or thermite are unnecessary (cue Max Photon saying that they may not have been necessary but that doesn't prove they weren't there), but one would have to read the full paper to find out. If anyone's got a link to a complete draft it would be very interesting to see it.

Dave

ETA: Now that I've read the full paper, I take this back - see my later post.

[lozenge124]

This looks a good deal more sensible and rigorous than Cherepanov, and the lengthy peer review looks like it's mainly due to major expansion of the scope of the paper rather than problems with the methodology. It's clearly suggesting that Bazant's model is over-simplified, and seems to be consistent with the core spires. It still seems to be saying that collapse propagation is expected, and one could infer from this that explosives or thermite are unnecessary (cue Max Photon saying that they may not have been necessary but that doesn't prove they weren't there), but one would have to read the full paper to find out. If anyone's got a link to a complete draft it would be very interesting to see it.

Dave

You can download the whole thing from the links in the upper right. Here is the pdf link:

http://arxiv.org/pdf/physics/0609105

The paper is quite mathematically involved, but Beck refutes Bazant (section II.D) and NIST (section IV), and concludes that the collapse would have been arrested were it not for a "wave of massive destruction" that knocked out the core columns.

We conclude that the buildings did not perish because of combined mechanical and heat damage to their primary zones, but because of yet another catastrophic event: a wave of massive destruction (WMD) that destroyed the CCs, following which the buildings collapsed to the ground.

(CC = core columns)

[Dave Rogers]

This paper isn't what it appears to be on the surface, is it? It looks like stealth trutherism, because the WMD isn't defined and isn't introduced until all the analysis has been completed. It certainly slipped under my radar on reading the abstract.

I have rather a problem with the following statement on page 6:

"From the properties of structural steel it is known that the yield strain under tension and compression are fairly similar, and is 21 − 25%."

Can a structural engineer check that this is saying what i think it is? It seems to me that the paper is asserting that a steel column can shorten by 25% of its original length without failing. That looks to me to be about two orders of magnitude too high. If so, it invalidates any collapse time analysis completely. I see Beck's using 13s and 11s for the collapses, which are at the lower end of the estimates I've seen.

The second issue I have is that the paper assumes that collapse initiation is due to progressive structural weakening to the point where the yield strength of the structure is no longer able to support the weight of the top block. That's not actually the NIST model that the paper claims to refute, in that it ignores the buckling of the perimeter columns due to pull-in from the floor trusses.

The destruction of columns from the aircraft impact seems to be greatly overestimated compared to the NIST estimates; I'm not sure how that affects the conclusions. I think it implicitly biases the model against collapse, because the response to the initial damage is chosen to be less than is required for collapse; increasing the initial damage estimate means that the magnitude of further damage required for collapse increases. Still, the paper seems to be suggesting that a 50% loss of support columns in WTC1, followed by a 50% strength reduction due to heating in the remaining columns, does not result in collapse initiation, which suggests a safety factor greater than 4. This seems unlikely, particularly since Beck quotes a safety factor of 3.5 in both towers.

The WTC7 analysis seems to be completely invalid because it assumes the whole building collapsed in 6.5 seconds from an initially undamaged state, which is a drastic oversimplification of the collapse mechanism.

Overall, this is a very clever paper, but I think it's a very clever piece of misinformation. I don't have the specialist knowledge to be certain.

Dave

[Sizzler]

Sizzler:

Another paper that contradicts Bazant & NIST is Charles Beck "Mathematical Models of Progressive Collapse and the Question of How Did the World Trade Centers Perish" available here:

http://arxiv.org/abs/physics/0609105

It has been submitted to ASCE J. of Engineering Mechanics and is apparently still in the peer review process (see submission history).

Thanks. Much appreciated.

[beachnut]

simple point:

he did publish a journal article that states progressive collapse is not possible due to free fall times, debris, etc. there were 3 reasons.

yes the paper i read has a lot of political garbage. does that make him scientifically crazy?

my point remains.

progressive collapse has been challenged in the mainstream for SOME of the reasons the truth movement challenges it.

So what is with all the crazy talk?
Simpler point: He is nuts and thinks bombs did 9/11 without saying in his body, he just says it in he intro! BIG reason why his first nut case paper did not see the light of day in a real journal. People publish garbage and it is published. His paper sucks, I am an engineer, I think it sucks. Please see others, AND I did include criques without such and crazy in them so you can get an idea why this paper sucks and is crazy! I presenting you with lots of reasons why this guys ideas on 9/11 are NUTS; you then ask me why?

Either show me why his into is not the biggest nut case intro I have ever seen; but then you agree later with stuff that says the same thing. I am correct his work is full of errors and his ideas are based on biased politically motivated 9/11 truth junk ideas. He put them in his paper!

The truth movement has no idea what is going on; So go ahead present the challenges (not this nut) to the official story of Impact, Fire, and collapse. BTW, calling the collapse any name may be a mistake, we will just call it the collapse how it looked on 9/11, the full scale model murder of Americans and others by terrorists. This nut case says the buildings could not fall without the mysterious WAVE, he means to say he agree with bombs in the WTC, he is wrong and kind of nuts on 9/11. He add all sorts of technical stuff to make his paper look smart, and then people easily dismiss his paper on merit and the biased junk he included as you have seen.

Darn you even posted his vanity crap from his web site. You posted it as if it had merit! It sucked.

You point does not stand, show some mainstream publication papers (without the nuts) that go against the way the WTC fell on 9/11, the chaotic fall of the towers, show me with sources and all?


Nut case stuff that is in his paper!

On the opinion of David Ray Griffin, U.S. government agents acting together with bin Laden used the terrorists for their mission , mined beforehand two towers and the neighboring 47- story skyscraper by explosives which were detonated in a while after the crashes.
You do not put this junk in so everyone knows you are a pathetic nut case making up stuff to support 9/11 truth. For the calm version of NUT, see http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/Progre-RebutCherepanovCritiqueOfBazZhouWTC-06.pdf

So I think he is crazy trying to make up stuff and pass it as real work, just because he wants explosives to have done it; he is nuts. = wrong

See this guy is attacking guys who made a model like a paper airplane is a model of a jet! The paper airplane flies, confirming that a plane flies! Wowzer. This nut case says NO, it did not fly, it can't fly and here is why! The nut case is wrong, the paper airplane does show why the jet flies. Models! Got to love them, but they are not real, they are models. Do not attack the model, make a better model. Our nut on 9/11 ideas failed.

[T.A.M.]

Hey look, it is a well known expert:


And he is arguing against Bazant in a peer reviewed engineering journal.

I thought these didn't exist?



He seems to understand the politics in science quite well, and from experience.

I thought free-fall collapse was invented by the truth movement? Why is this expert endorsing lies?

Why did the peer review process not catch this bold face lie?

Could disinformation be rampant on both side of the spectrum?

Or just one?

Why are you asking these questions?

TAM:)

[Newtons Bit]

This paper isn't what it appears to be on the surface, is it? It looks like stealth trutherism, because the WMD isn't defined and isn't introduced until all the analysis has been completed. It certainly slipped under my radar on reading the abstract.

I have rather a problem with the following statement on page 6:

"From the properties of structural steel it is known that the yield strain under tension and compression are fairly similar, and is 21 − 25%."

Can a structural engineer check that this is saying what i think it is? It seems to me that the paper is asserting that a steel column can shorten by 25% of its original length without failing. That looks to me to be about two orders of magnitude too high. If so, it invalidates any collapse time analysis completely. I see Beck's using 13s and 11s for the collapses, which are at the lower end of the estimates I've seen.

The second issue I have is that the paper assumes that collapse initiation is due to progressive structural weakening to the point where the yield strength of the structure is no longer able to support the weight of the top block. That's not actually the NIST model that the paper claims to refute, in that it ignores the buckling of the perimeter columns due to pull-in from the floor trusses.

The destruction of columns from the aircraft impact seems to be greatly overestimated compared to the NIST estimates; I'm not sure how that affects the conclusions. I think it implicitly biases the model against collapse, because the response to the initial damage is chosen to be less than is required for collapse; increasing the initial damage estimate means that the magnitude of further damage required for collapse increases. Still, the paper seems to be suggesting that a 50% loss of support columns in WTC1, followed by a 50% strength reduction due to heating in the remaining columns, does not result in collapse initiation, which suggests a safety factor greater than 4. This seems unlikely, particularly since Beck quotes a safety factor of 3.5 in both towers.

The WTC7 analysis seems to be completely invalid because it assumes the whole building collapsed in 6.5 seconds from an initially undamaged state, which is a drastic oversimplification of the collapse mechanism.

Overall, this is a very clever paper, but I think it's a very clever piece of misinformation. I don't have the specialist knowledge to be certain.

Dave

I've downloaded the paper, but don't have time to really look at it yet. It's a bit too long and in depth for me to print out and peruse over the porcelain throne.

You are correct in that the yield strain of steel is not 25%, it's 0.2%. That's a factor of "oops" of 125.

GregoryUlrich has calculated the Demand-to-Capacity ratio of the columns at in-service loads at about 0.3.

[PhantomWolf]

I've never heard that from the CD-hypothesis group.

They all state either, essentially or near free-fall.

NIST confirms this statements by using the same words. However many debunking sites try to discredit this. Why?

Because it wasn't at free fall speed, personally I don't even like at near free fall.

The original Truther claim was that it was faster than freefall, this then changed to at freefall, and finally to near freefall speeds.

The actual collapse times, not including the parts of the cores wich remained standing were approximately 16 seconds for WTC 2 (with the first panels hitting at 9 seconds) and 18 seconds for WTC 1 (with the first pannels hitting at 10 seconds.) Personally I think that you'd be hard pressed to convince a cop that you were nearly doing the speed limit when caught doing 70-80mph over it, but this to me is exactly what the language "near freefall" attempts to do.

[Dave Rogers]

I've never heard that from the CD-hypothesis group.

They all state either, essentially or near free-fall.

Try googling "faster than freefall". In between the fairground rides, I found the following:

http://freedomisforeverybody.blogspot.com/2007/10/proof-wtc-tower-2-falls-3-times-faster.html - "Proof WTC2 tower falls faster than freefall."

http://www.drjudywood.com/pdf/070802_DEWandthewtc.pdf - "Directed Energy Weapons and the World Trade Center", in which Judy Wood claims a faster-than-freefall collapse time.

http://kendwebber.typepad.com/the_coffee_cup_project/2007/04/debunking_james.html
"Buildings fall at only TWO speeds, freefall gravity speed, OR... faster than freefall. The ONLY way possible for a building to fall at faster than freefall speed is through explosive force. Exploding demolitions create a vacuum. It is that vacuum that "pulls" a building down into its own footprint at faster than gravity speeds. "

http://911truth.ozempire.com/wtc.html
"Again we see the first tower collapse in 10.5 seconds and the second tower collapse in just 8.4 seconds, slightly faster than freefall speed, which is known to be about 9.2 seconds."

Most of these sites were put up in 2007. Faster than freefall is alive, well, and destroying braincells at a website near you!

Dave

[Gazpacho]

So not ALL the experts agree. This expert agrees that free-fall is not possible under progressive collapse. So which expert to I believe?
Certainly do not believe the expert who spends two pages of a proposed scientific paper ranting about politics and various other things that have no bearing on his hypothesis.

yes the paper i read has a lot of political garbage. does that make him scientifically crazy?
It means that, despite 30 years as a professor, he presently has no idea how to present a scientific result.

You can go to a library and pick any English-language engineering journal off the shelves, and look through it for a paper that uses political claptrap to support its result. You will not find one. It is not science. By submitting such a paper for publication, an author is basically saying (1) he has not shown the paper to his scientific peers, who would have told him to remove the claptrap, and (2) he holds the journal and its editors in contempt (In case there's any doubt, Cherepanov says this outright at the end of the paper.)

Briefly, someone whose goal is to change minds and defend scientific integrity does not do that.

[Dave Rogers]

I've downloaded the paper, but don't have time to really look at it yet. It's a bit too long and in depth for me to print out and peruse over the porcelain throne.

You are correct in that the yield strain of steel is not 25%, it's 0.2%. That's a factor of "oops" of 125.

GregoryUlrich has calculated the Demand-to-Capacity ratio of the columns at in-service loads at about 0.3.

I'm still working through it, but it's tough going. There doesn't appear to be anything obviously wrong with the maths. It's the numbers he's plugging in to the maths that are the problem.

Beck says that the core consisted of 51 columns, all of them 22 by 55 inches, made up from steel plates of varying thickness and yield strength as a function of height. He's using 4.5x10^8 kg for the mass, allowing the column strength but not the mass distribution to vary with height, and from his numbers I get a safety factor of 9.3 at floor 97 (or a Demand-to-Capacity ratio of 0.107 if you prefer it that way up). That's a long way off Gregory's numbers.

Next, he's assuming that, during the collapse, the support columns exert their ultimate yield force over the entire shortening phase, that the entire shortening phase is elastic, and that their yield point is at 20% strain. He's not just getting the strain a couple of orders of magnitude out, he's ignoring Hooke's law as well, but compensating in part by ignoring plastic deformation. Based on all that I get his figure for the energy to collapse floor 97 as 3.75GJ. I'm not entirely sure I follow Gregory's analysis completely, but I think he gets something more like 1.3GJ to collapse floor 97 - Gregory, any comments?

That's about as far as I've got, but it seems that Beck has both overestimated the static strength of the structure, and overestimated the resistive force during collapse relative to his overestimate of the static strength. I suspect that if those overestimates are scaled down sensibly, he hasn't got a conclusion left. And I'm beginning to understand why this hasn't got through peer review even though it was first submitted last October.

I'd appreciate any checking of these numbers. I've been wrong before, and I'm sure I'll be wrong again.

Dave

[Dave Rogers]

Just a few more observations before I give up on this paper.

Firstly, in section 6, "Discussion", part 1, Beck makes the comment that the floor material cannot impact the columns vertically, as there is no provision in his model for the collapse front to grow vertically. It will therefore impact only on the floor below, which he references as having a load capacity of 0.02 times the mass of the tower. Even if his overestimates of yield strength and crushing resistance were correct, this section totally invalidates all his arguments, as it outlines a scenario in which the collapse proceeds by successive floor collapse, leaving the support columns to collapse subsequently (which agrees rather better with the observed collapse than the one-dimensional approximation anyway).

Secondly, the appendix on the WTC7 collapse appears as badly flawed as the main body of the paper, but the results are less obvious. Beck calculates that the collapse initiation and the collapse time are consistent with the same degree of weakening of the building, which on the face of it appears reasonable. However, this requires global weakening of the entire structure to an unrealistic degree. Beck's misrepresentation of the NIST provisional collapse hypothesis results in his conclusion that additional damage was required for initiation; he makes no attempt to model or even discuss a progressive failure as envisaged by NIST and evidenced by the collapse of the east mechanical penthouse, and even avoids any mention of it in his formulation of the NIST scenario. I suspect that a more reasonable set of parameters in a collapse model would require very much less global weakening to give agreement with the observed collapse time; in fact, other models give good agreement with no global weakening at all.

Overall, then, Beck seems to be misrepresenting the conclusions of the NIST report and overestimating the strength of the Twin Towers grossly in order to get to a conclusion that some additional damage was needed both to initiate and to propagate the collapse, and misrepresenting the provisional NIST WTC7 collapse model in order to reach a conclusion that some unknown event was needed to initiate, but not to propagate, the collapse.

I find this perhaps the most disturbing piece of truther "science" that I've seen so far. From the quality of the mathematical analysis, Beck is quite capable of understanding what he's getting wrong. I have a hard time believing he's simply misinformed.

Dave

[Apollo20]

Dave Rogers:

Yes, I agree with you about Beck's paper. He introduces his "wave of massive destruction", (WMD), immediately after 10 pages of high-powered math without any explanation of what a WMD could possibly be!

Where is the science in that?

I would say that WMD stands for Waffley Mathematical Disinfo.....

[lozenge124]

Dave Rogers:

If you care to email what you posted here to Charles Beck, I'm sure he'd be interested in the feedback and maybe can respond. He posted in the physorg forum 911 thread for comments back when the paper was in its first draft.

[lozenge124]

Dave Rogers:

Yes, I agree with you about Beck's paper. He introduces his "wave of massive destruction", (WMD), immediately after 10 pages of high-powered math without any explanation of what a WMD could possibly be!

Where is the science in that?

I would say that WMD stands for Waffley Mathematical Disinfo.....

He's just saying that his analysis shows some other energy source was required, beyond the potential energy of the upper block, to knock out the core columns. I don't think it would add anything to the paper to then go into a detailed discussion of explosives/thermate (or whatever), quantities required, positioning, man-hours etc... its beyond the scope of the paper, and he's being appropriately circumspect keeping the paper on point. (The "WMD" acronym is a little unfortunate though...)

[beachnut]

Dave Rogers:

Yes, I agree with you about Beck's paper. He introduces his "wave of massive destruction", (WMD), immediately after 10 pages of high-powered math without any explanation of what a WMD could possibly be!

Where is the science in that?

I would say that WMD stands for Waffley Mathematical Disinfo.....
Bush may find his WMD before Beck does. I guess Beck thinks it is politically correct to blame a WMD.

[Dave Rogers]

(The "WMD" acronym is a little unfortunate though...)

A little unfortunate? If Beck hasn't heard of the abbreviation "WMD" and isn't aware of its political implications, then he's been living in a much deeper hole than the one they found Saddam in. The "WMD" acronym isn't "unfortunate", it's a clear dig at the Bush administration, and an obvious one.

As for passing my comments on to Beck, given that he's spent over a year making major revisions of the paper in which he's progressively reduced the resistance of the structure to collapse (I noticed that the first draft assumed that the collapse was opposed by a constant force equal to the yield point of the structure, which is greater than the static force it exerts!), is still way in excess of a reasonable number, and hasn't changed his conclusion in the slightest, together with the fact that he's made no effort to describe the NIST results and hypotheses correctly, then my comments probably won't make a lot of difference. Feel free to invite him over here if you know him, but I don't much fancy barging into PhysOrg as a rank newbie and getting into a pointless argument with someone who's reasoning backwards from his conclusions.

Dave

[Sizzler]

Thanks for all your input guys. I think his paper is crazy too.

However I learned that;

Because his "toned down" paper was published in a scientific journal, and was peer reviewed, it just demonstrates that not all members of the scientific community accept the "progressive model", no matter how crazy their alternatives are.

Also, certain thruther claims, do have some "scientists", who get published in journals, thinking about alternatives.

It is too bad that most alternatives to "progressive theory" are rather crazy.

Is that why certain people here hold on to the 'theory' with all their might?

Is the only alternative to "progressive collapse", CD?

[beachnut]

Thanks for all your input guys. I think his paper is crazy too.

However I learned that;

Because his "toned down" paper was published in a scientific journal, and was peer reviewed, it just demonstrates that not all members of the scientific community accept the "progressive model", no matter how crazy their alternatives are.

Also, certain thruther claims, do have some "scientists", who get published in journals, thinking about alternatives.

It is too bad that most alternatives to "progressive theory" are rather crazy.

Is that why certain people here hold on to the 'theory' with all their might?

Is the only alternative to "progressive collapse", CD?
So who published his paper with WMD in it? Think some peers messed up? WMD? Not crazy, bat crap crazy.

Bad papers can make publication. Wow. Bad books get published too.

But 9/11 truth has yet to present facts and evidence to support their ideas of WMDs, thermite, bombs, et al

[beachnut]

He's just saying that his analysis shows some other energy source was required, beyond the potential energy of the upper block, to knock out the core columns. I don't think it would add anything to the paper to then go into a detailed discussion of explosives/thermate (or whatever), quantities required, positioning, man-hours etc... its beyond the scope of the paper, and he's being appropriately circumspect keeping the paper on point. (The "WMD" acronym is a little unfortunate though...)
But he is wrong. Kind of ironic after his paragraphs of 9/11 truth lies! He even uses DRG. If you use DRG, you have proven by citing his hearsay junk you are not really capable of science or very good fiction.

He should have read NIST, or watched the video tape of 9/11. How can anyone be so stupid? Oh, yes, I keep forgetting he put in his drafts tons of lies from 9/11 truth!

[Sizzler]

So who published his paper with WMD in it? Think some peers messed up? WMD? Not crazy, bat crap crazy.

Bad papers can make publication. Wow. Bad books get published too.

But 9/11 truth has yet to present facts and evidence to support their ideas of WMDs, thermite, bombs, et al

They have yet to present their evidence in a peer reviewed mainstream paper.

Collapse time seems to be a big issue and as mentioned above, has been discussed in the mainstream.

Aside from theory;

There are claims of thermite/thermate residue, microspheres, and unreacted thermite.

Yes, all of the chemicals needed were found naturally in the WTC.

It is up to the truth movement scientists to rule out natural occurance of these observations.

Such tests have not been published yet and until then, you are right in stating that there is no scientifically confirmed evidence.

At the end of the day, debunking is no better than CT. That is why I remain skeptical of the official hypothesis, yet unable to accept the alternative.

Good science will rise to the top given time.

[Newtons Bit]

It is up to the truth movement scientists to rule out natural occurance of these observations.

They won't. Whatever they find is proof of their belief. Whatever they don't find is similarly evidence.

They're not going to look for other causes, they're trying to affirm a belief.

[Sizzler]

They won't. Whatever they find is proof of their belief. Whatever they don't find is similarly evidence.

They're not going to look for other causes, they're trying to affirm a belief.


Time will confirm or reject your opinion.

[beachnut]

They have yet to present their evidence in a peer reviewed mainstream paper.

Collapse time seems to be a big issue and as mentioned above, has been discussed in the mainstream.

Aside from theory;

There are claims of thermite/thermate residue, microspheres, and unreacted thermite.

Yes, all of the chemicals needed were found naturally in the WTC.

It is up to the truth movement scientists to rule out natural occurance of these observations.

Such tests have not been published yet and until then, you are right in stating that there is no scientifically confirmed evidence.

At the end of the day, debunking is no better than CT. That is why I remain skeptical of the official hypothesis, yet unable to accept the alternative.

Good science will rise to the top given time.
You talk of great woo. It has been 6 years, the 9/11 truth movement is base on lies and false information. Please if you have one piece of evidence to prove any 9/11 truth conclusions now is the time to collect the Pulitzer Prize and stop being so truthy about it.

I am not calling you a 9/11 truth dolt, but you sure do spread the crap from 9/11 truth and try too hard to support idiots' papers. I think, I am always wrong though. But thermite, give me a break! There is not thermite planted in the WTC, I bet your life on it! Jones made up thermite 4 (FOUR) years after 9/11! He has as much knowledge on 9/11 as Charlie Sheen and Rosie O!

Very noble of you to lend credence to nut case ideas of thermite, really polite, but since you are being mislead my idiots of 9/11 truth it is not your fault. But if you think they are viable theories cool, my kids and grandkids your age will have less competition intellectually in the world you compete in.

Bring on evidence, so far you are batting 100 percent 9/11 truth junk, and you seem to avoid any real rational or logical evidence. Why? You sound like a covert LCFC supporter. Why?

It takes just a little logical thinking to see the idiots of 9/11 truth are making it up; do you have what it takes?

[Pardalis]

At the end of the day, debunking is no better than CT. That is why I remain skeptical of the official hypothesis, yet unable to accept the alternative.


At the end of the day, you got to ask yourself: why on earth would they CD the towers?

The idea is preposterous.

[Gravy]

Time will confirm or reject your opinion.It's 2008. They've been doing this for years.* You haven't noticed?


*And have gotten nothing right, remember?

[Gravy]

At the end of the day, debunking is no better than CT. That is why I remain skeptical of the official hypothesis, yet unable to accept the alternative.
Let me get this straight: correcting hundreds of false claims and statements about an important subject is just as bad as making the false claims and statements?

Would you like to re-think that, Sizzler, or would you prefer to be taken for the biggest fool who's ever posted here?

[Sizzler]

It's 2008. They've been doing this for years.* You haven't noticed?


*And have gotten nothing right, remember?

I've heard this kind of argument plenty around here.

It is pretty weak in my opinion, especially considering we are still waiting for the wtc7 report.

what's the rush anyway?

[Sizzler]

Let me get this straight: correcting hundreds of false claims and statements about an important subject is just as bad as making the false claims and statements?

Would you like to re-think that, Sizzler, or would you prefer to be taken for the biggest fool who's ever posted here?

correcting false statements is one thing, and I commend anyone for doing such.

for example;

claim; wtc fell faster than free-fall

respose; no it didn't. it has been timed at near 15 seconds +/- (video evidence supports such)

but debunking is in the same realm of ct when it only offers alternatives without any scientific basis.

for example;

claim: microspheres found in dust

response: that can be numerous things such as __________ or __________.

-this is in the same realm of ct because no scientific evidence backs the response.


so i'll retract my former statement and suggest that debunking responses not backed by scientific inquiry are no better than ct. correcting false statements with observable facts is a different story and you guys do a good jobn with that;)

[T.A.M.]

Button up that skirt, the slip is showing.

TAM;)

[Dave Rogers]

but debunking is in the same realm of ct when it only offers alternatives without any scientific basis.

for example;

claim: microspheres found in dust

response: that can be numerous things such as __________ or __________.

-this is in the same realm of ct because no scientific evidence backs the response.

You're missing the point. It goes more like this.

Claim: Microspheres found in the dust can only have been formed due to high temperatures prior to or during the collapse, which proves there was thermite used in initiating the collapse.

Response: The microspheres have many other possible origins, therefore there is no proof that thermite was used in initiating the collapse.

Given the vast body of evidence in favour of the conventionally accepted narrative of the attacks, the burden of proof is on those who claim an alternative sequence of events. If that proof is shown to be invalid, then we revert to the vast body of evidence. That may not be the same as "proving the official story", but it's still valid.

Dave

[Newtons Bit]

I'm still working through it, but it's tough going. There doesn't appear to be anything obviously wrong with the maths. It's the numbers he's plugging in to the maths that are the problem.

Beck says that the core consisted of 51 columns, all of them 22 by 55 inches, made up from steel plates of varying thickness and yield strength as a function of height. He's using 4.5x10^8 kg for the mass, allowing the column strength but not the mass distribution to vary with height, and from his numbers I get a safety factor of 9.3 at floor 97 (or a Demand-to-Capacity ratio of 0.107 if you prefer it that way up). That's a long way off Gregory's numbers.

Next, he's assuming that, during the collapse, the support columns exert their ultimate yield force over the entire shortening phase, that the entire shortening phase is elastic, and that their yield point is at 20% strain. He's not just getting the strain a couple of orders of magnitude out, he's ignoring Hooke's law as well, but compensating in part by ignoring plastic deformation. Based on all that I get his figure for the energy to collapse floor 97 as 3.75GJ. I'm not entirely sure I follow Gregory's analysis completely, but I think he gets something more like 1.3GJ to collapse floor 97 - Gregory, any comments?

That's about as far as I've got, but it seems that Beck has both overestimated the static strength of the structure, and overestimated the resistive force during collapse relative to his overestimate of the static strength. I suspect that if those overestimates are scaled down sensibly, he hasn't got a conclusion left. And I'm beginning to understand why this hasn't got through peer review even though it was first submitted last October.

I'd appreciate any checking of these numbers. I've been wrong before, and I'm sure I'll be wrong again.

Dave

I concur with this. Beck is using the column sizes of the basement at the collapse initiation point, which gives far too much strength. And then he allows the columns to shorten over 20% of the length, which means they absorb at least 144 times more energy than they conceivably can.

[AZCat]

Thanks for all your input guys. I think his paper is crazy too.

However I learned that;

Because his "toned down" paper was published in a scientific journal, and was peer reviewed, it just demonstrates that not all members of the scientific community accept the "progressive model", no matter how crazy their alternatives are.

I don't think his paper (toned down or not) has yet been published. It appears it is still being reviewed.

[AZCat]

I concur with this. Beck is using the column sizes of the basement at the collapse initiation point, which gives far too much strength. And then he allows the columns to shorten over 20% of the length, which means they absorb at least 144 times more energy than they conceivably can.

That's gross.


:p

[Sizzler]

I don't think his paper (toned down or not) has yet been published. It appears it is still being reviewed.

peep op.

[AZCat]

peep op.

Whoops, I thought we were talking about the Beck paper.