RFC: Bazant and Zhou Simple Analysis refuted

[beachnut]

I've an other question Apollo20,

page 10 from http://www.nistreview.org/WTC-REPORT-GREENING.pdf

Prof Wierzbicki said that it takes 1.139*10^6 J to cut an exterior column,
then multiplying times 236+47*6.7 gives the often mentioned E1 value 0.63 GJ, Bazant independently derived 0.5 GJ from first principles.

In the paper we can read: Thus Wierzbicki considers floor support failure under lateral impact loading while Bažant’s considers the failure of the floor supports under axial impact loading. The fact that the energy calculated in each of these cases is about the same suggests that the energy dissipated in a floor collapse is relatively insensitive to the mode of failure of the support structures. This is a common observation in studies of collisions of large objects involving complex structures such as aircraft, automobiles, trains, and ships.

What I still don't understand is that the toppling of the block is crucial for a collapse that continues, I'm not really into columns and axial loads etc but does the above conclusion not really contradict that the toppling is relevant ?

And I don't know what Heiwa means with that single column, but it was no block standing on a single column but a large amount of columns, assume 80% is still intact then the 0.5GJ could be multiplied by 0.8, a huge amount of energy is needed.

The destroy is not directly possible form potential energy, first kinetic energy should be garthered. But in a slow movement there is not much kinetic or rotational energy. In 1d you can proof that it is absorbed, 3d is absolutely incredibly difficult but I still think it is amazing that your energy calculation (based on radial impact) is the same as a real crushing of the story and therefore the approach 3d -> 1d could be valid.

ps. and I don't know exactly where the fireproofing was dislodges, which core columns but that should give another factor. But the static load is still really a fraction of the maximum load

Does this means each aircraft impact alone had enough energy, (huge amount of energy is needed) at 2.8GJ and 4.3GJ, to cut all the columns! More than once!?

And the tops falling had more than enough energy to destroy the floor below! Since a single floor can only hold itself and 10 or 11 floors, any thing over 6 floors falling any distance would make the floors below fail. These are the facts of the case and you can see the results in video recorded on 9/11. Debunking 9/11 truth is like cheating and having the answers already. Got some facts yet 9/11 truth?

You should weigh the floors and see how many it takes to fall or just land on a single floor before the floor fails, making the shell peel off, and the core unable to stand alone. Like you see on 9/11! A full scale model with no CD or thermite added like 9/11 truth lies about.

a slow movement there is not much kinetic or rotational energy

WHAAAATTTT? Did you know moving only 1.85 meters, the WTC small top packs more than .5GJ. Oops, slow moving big mass is a lot of KE! U B Wrong. Hate to do the #s on the big top! Ouch. This means if it moves a distance of one floor, there is 1GJ! And the big top has a lot more falling just half a floor, would have a KE of 1.85! Small movement of big mass is a lot of energy, this is why a BIG slow train can not stop fast. This is why a slow ship hitting a big iceberg sinks!

 

[tsig]

Because release of potential energy of a mass above (cause) does not cause global collapse due to lack of strain energy of the structure below (effect) as alleged by NIST and Bazant (and Zhou).

The two are not related! First of all the potential energy must be applied to the structure below - there is no evidence for that.

NIST and Bazant assume the application of potential energy is an impact at high velocity on the structure below. No evidence for that.

If the application is at low velocity, which is the case, stresses in the structure below (and above!) are hardly affected and will evidently be same before and after loading.

It like hitting a nail (structure below) with a hammer (potential energy released). Too little speed nothing happens. To much speed nail bends and hammer slides off the nail and the energy is lost. It is not easy to hit a nail.

Bazant actually assumes that WTC1 is hammered 90 times; mass above (rigid and stiff all the time) first drops one floor that magically disappeared due to heat (the initiation zone) and crushes the floor below, i.e. deforms/buckles the supporting columns there and sweeps them out of the way (no evidence for that), then it drops another floor with same effect, then again ... 90 times. Evidently the rubble does not show any buckled columns, like that. Anywhere.

So Bazant's and Zhou's basic assumption is 100% wrong. Garbage in = garbage out.

NIST has abandoned the hammer/nail theory and suggests (FAQ Dec 2007) that 5-10 floors (in mass above) suddenly dropped down in the initiation zone (cause) and overloaded the first floor of the structure below (effect).

There is no evidence for that cause at all. It is pure fantasy. Note that NIST actually assumes that the mass above first disintegrates (before it was solid and stiff) and that now some subparts of the mass above (floors) suddenly drop down and do the hammering!

But again, there is no evidence that even one floor suddenly dropped!

In my article for children I just politely ask NIST and Bazant to re-do their analysises. No big deal! Very often mistakes are done in technical papers for various reasons.

Have you ever used a hammer?

 

[twinstead]

Heiwa don't you think it presumptuous that you ask NIST and Bazant to 're-do' their analysis? I'm sure their first response would be "just who the hell are YOU?"

What I mean is what if NIST and Bazant consider you to be somebody who has no idea what he is talking about questioning their conclusions?

Is there something you are expert on that you would consider some moron trying to tell you what he thinks about it irrelevant because he doesn't know what he is talking about?

What would your response be if Bazant or any of the EXPERT contributers to NIST said you didn't know what you were talking about?

 

[tsig]

I like Gurich's paper about overload caused by the mass above on the structure below.

The mass above is of course a hotch potch of structural items so it easiest just to look at one of them and apply the theory to it, e.g. core column #501

It is an H-beam with two flanges 17x3.5 inch connected by a 2.2x12.6 inch web.

In metric terms the flanges are 430x90 mm and the web is 56x320 mm. The cross area is about 950 cm², i.e. the column is very solid. It weighs 750 kgs/m. It may carry as much as 700 tons transmitted to it from the floors above, i.e. each floor above transmits about 50 tons to the column through bolted connections.

The compressive stress in this core column at floors 94-98 is then abt 736 kgs/cm² or 74 MPa or 30% of the yield stress of the steel. The (smallest) moment of inertia I of this section is about 120 000 cm4 and its radius of gyration is of the order 35 cms. With a free length of 350 cms the slenderness ration is 10! Removing three floors as support and the free length is 1 400 cms and the slenderness ratio is still only 40! The thick steel plates, 56 and 90 mm cannot buckle under any circumstance when the compressive stress is only 30% of yield stress even if the temperature is 500°C.

Anyway our humble experts at NIST suggest that a part of this column 'buckles' - probably it bends - in the initiation zone and then disappears (none has been found) so that the upper, top part - 700 tons - most of it floors bolted to it, drops down on the lower part - and hits it with an impact force!

NIST thus assumes that the upper part of one column hits the lower part of the same column without missing it. What happens then? I would assume that most bolted floor connections of the upper part shear off due to the impact.

And that should be the end of it. Hostile comments are always welcome as the houris await me in Paradise.

PS There are many photos of a woman standing waving on floor 93 of WTC 1 at the hole in the North wall. Not far behind her, inside WTC1 is core column #501.

The women died is that enough truth for you.

 

[Heiwa]

Heiwa - went to your site and must say....

"wow"

You compare the collapse to a child jumping on a bed?

You suggest building a model of the WTC out of plwood and some metal, and use a "water tank" to simulate the upper WTC block?

Then put a "pan of diesel oil on fire to simulate the jet fuel?

Ouch - even as a layman to structural engineering, I can see all kinds of wrong with your test....

I don't remember seeing a vast tank of water in the WTC that covered the entire floor(s).

I don't remember seeing it covered in plywood!

You don't model the trusses, the hat truss, the inner core and outer wall being pulled in by the sagging floor, you simply build four poles to hold up a water tank, surround it with plywood, fill that space with debris and a pan of diesel oil, and catch it on fire....

Can you really state is an accurate test?

You have read the NIST report, right?

I see that helpful henchmen of Nist are at it again and need some assistance to understand. The purpose of the model is only to see what happens to a steel column under 30% of yield compression when heated to 500°C, which apparently is a condition for later collapse. Nothing happens. And this is apparently one reason why Nist has abandoned that idea and now suggests that complete floors, 6 or 11, dropping down initiated the collapse.

But Nist fails to explain why floors dropped down at all. Somebody forgot to secure them? Somebody removed the bolts? These NIST FAQ December 2007 answers are really hilarious.

 

[Heiwa]

Heiwa don't you think it presumptuous that you ask NIST and Bazant to 're-do' their analysis? I'm sure their first response would be "just who the hell are YOU?"

What I mean is what if NIST and Bazant consider you to be somebody who has no idea what he is talking about questioning their conclusions?

Is there something you are expert on that you would consider some moron trying to tell you what he thinks about it irrelevant because he doesn't know what he is talking about?

What would your response be if Bazant or any of the EXPERT contributers to NIST said you didn't know what you were talking about?

Well, I was in fact corresponding with NIST about steel columns not crumpling up (buckling) at 500°C as contributing to collapse and NIST replied with a reference to floors dropping down instead + link to FAQ December 2007. Maybe they had read my CV?
If somebody told me I don't know what I am talking about, I am of course curious to know what technical aspect of the problem under discussion I have misunderstood. So we discuss collapse inititation. Crumpling columns are apparently not possible. Dropping floors? Frankly speaking, I cannot follow any logic there. Defective welding? I have no details but doubt it causes global collapse.
You need plenty of energy not only to initiate but also to complete global collapse of a structure and the potential energy available is too little.

 

[tsig]

Well, I was in fact corresponding with NIST about steel columns not crumpling up (buckling) at 500°C as contributing to collapse and NIST replied with a reference to floors dropping down instead + link to FAQ December 2007. Maybe they had read my CV?
If somebody told me I don't know what I am talking about, I am of course curious to know what technical aspect of the problem under discussion I have misunderstood. So we discuss collapse inititation. Crumpling columns are apparently not possible. Dropping floors? Frankly speaking, I cannot follow any logic there. Defective welding? I have no details but doubt it causes global collapse.
You need plenty of energy not only to initiate but also to complete global collapse of a structure and the potential energy available is too little.

Do you do English?

 

[twinstead]

Well, I was in fact corresponding with NIST about steel columns not crumpling up (buckling) at 500°C as contributing to collapse and NIST replied with a reference to floors dropping down instead + link to FAQ December 2007. Maybe they had read my CV?
If somebody told me I don't know what I am talking about, I am of course curious to know what technical aspect of the problem under discussion I have misunderstood. So we discuss collapse inititation. Crumpling columns are apparently not possible. Dropping floors? Frankly speaking, I cannot follow any logic there. Defective welding? I have no details but doubt it causes global collapse.
You need plenty of energy not only to initiate but also to complete global collapse of a structure and the potential energy available is too little.

You have been shown where you are wrong and/or where you don't know what you are talking about. Heck, since I'm not one to even try to understand much of this, I even showed this thread to a couple friends over at the engineering part of my local university and THEY said you don't know what you are talking about. Every person on this forum whom I suspect does know what he talking about says you don't know what you are talking about.

I mean no disrespect, of course, but this worries me. As a layman I need to rely on experts, and if all the experts who disagree with you are wrong, If the consensus of experts world wide is wrong, if the building code changes occurring world wide because of the NIST's findings are wrong, then there is something seriously wrong with the engineering community, and we are in grave danger walking into any large building anywhere.

Don't you agree?

 

[Norseman]

The mass above is of course a hotch potch of structural items so it easiest just to look at one of them and apply the theory to it, e.g. core column #501

It is an H-beam with two flanges 17x3.5 inch connected by a 2.2x12.6 inch web.

In metric terms the flanges are 430x90 mm and the web is 56x320 mm. The cross area is about 950 cm², i.e. the column is very solid. It weighs 750 kgs/m. It may carry as much as 700 tons transmitted to it from the floors above, i.e. each floor above transmits about 50 tons to the column through bolted connections.

The compressive stress in this core column at floors 94-98 is then abt 736 kgs/cm² or 74 MPa or 30% of the yield stress of the steel. The (smallest) moment of inertia I of this section is about 120 000 cm4 and its radius of gyration is of the order 35 cms. With a free length of 350 cms the slenderness ration is 10! Removing three floors as support and the free length is 1 400 cms and the slenderness ratio is still only 40! The thick steel plates, 56 and 90 mm cannot buckle under any circumstance when the compressive stress is only 30% of yield stress even if the temperature is 500°C.

Heiwa, are you aware of the fact that you picked the measurements for the section of column 501 that goes from floor 92 - 95. When I add in the extra floors using your 50 ton figure I find that this section was loaded to 40% of yield stress between floor 92 and 93. I get the same load factor for the two next column sections above.

I assume you found your measurements here:
http://wtcmodel.wikidot.com/cc501

I have not checked how you found that 50 ton figure, but maybe I should. And why this obsession with just 500 degree celsius, why not 600 or 700 degrees celsius. The later temperatures makes a dramatic difference.

 

[Major_Tom]

Apollo20 writes:

And as for buckling, .... let's say there was very little buckling, and the main mode of core column failure was fracture at the weld planes. That was possible "without any evil expeditious external energy input" wouldn't you say?

Same for the perimeter. Very little buckling observed in the rubble.

Very little buckling in the core, very little in the perimeter.

What do you have left?

No core box columns recovered from the collapse initiation zones.

38 foot giant rectangular things. Where did they go?

I am wondering if you could flesh out the mechanism that you believe might be able to account for the weld planes to fail at the initiation.

And don't forget about the lack of perimeter buckling seen in the rubble while explaining the progressive collapse mechanism.




The inability to provide buckled core columns from the collapse initiation regions shows that the Bazant theory of collapse initiation is not true.

You simply wish it to be true.

I found one of your damaged core box columns from the airplane strike. It has a dent in it's side but no buckle.



Norseman writes:

The crumbled up perimeter column looks very much like it was overloaded by the upper block during the collapse initiation.

This type of damage is the rare, rare exception.

You won't find many pieces like that among the debris, almost none.


Again, "faith" in buckling is all you have.

 

[Major_Tom]

Myriad writes:

Most of the columns were measurably bent, many of them to a degree that's easily visible even in photographs.

Of core columns this is simply untrue.

Of perimeter columns you will see bending but very little plastic buckling.

They could not match specific columns to specific as-built positions, for reasons they explained,

This is the center of the lie.

You point to debris which is so thoroughly mangled it is unrecognizable.

Please show me some core and perimeter columns that are so badly damaged they are on the verge of being unrecognizable.


The core columns in these regions were not recovered because they would ruin the power of the lie.


Judy Wood claims "dustification", and yet cannot show one partially "dustified" column.

Steven Jones claims "angle cuts" or "thermite cuts", yet cannot find more than a single angle-cut column (which is actually an oxy-lance cut).

You seem to claim that the evidence in this region was unrecognizable, yet you can't show core box columns that are partially unrecognizable.



So they are either totally destroyed or in remarkably good shape?

Your notion of the core "buckling" contains as much evidence as "dustification", and requires as much faith.



These lies have simply been repeated so many times that many people believe they are true.

 

[Myriad]

They could not match specific columns to specific as-built positions, for reasons they explained,

This is the center of the lie.

You point to debris which is so thoroughly mangled it is unrecognizable.

Please show me some core and perimeter columns that are so badly damaged they are on the verge of being unrecognizable.

Pardon me. I should have been more truthful, and said, "They could not match specific columns to specific as-built positions, for reasons they explained, but which since you haven't read their explanation, will be mysterious and suspicious to you."

Why don't you go read what those reasons actually are, and then we'll talk about this some more? I'll wait. (Hint: it has nothing to do with how "mangled" the columns were.)

Respectfully,
Myriad

 

[DGM]

Myriad writes:



Of core columns this is simply untrue.

Of perimeter columns you will bending but very little plastic buckling.




This is the center of the lie.

You point to debris which is so thoroughly mangled it is unrecognizable.

Please show me some core and perimeter columns that are so badly damaged they are on the verge of being unrecognizable.


The core columns in these regions were not recovered because they would ruin the power of the lie.


Judy Wood claims "dustification", and yet cannot show one partially "dustified" column.

Steven Jones claims "angle cuts" or "thermite cuts", yet cannot find more than a single angle-cut column (which is actually an oxy-lance cut).

You seem to claim that the evidence in this region was unrecognizable, yet you can't show core box columns that are partially unrecognizable.



So they are either totally destroyed or in remarkably good shape?

Your notion of the core "buckling" contains as much evidence as "dustification", and requires as much faith.



These lies have simply been repeated so many times that many people believe they are true.

You need a new hobby! Everything you have shown only supports what should have happened. Columns break at the weakest point, the weld. It's a shame you can't justify this in your mind.

 

[Major_Tom]

You need a new hobby! Everything you have shown only supports what should have happened. Columns break at the weakest point, the weld. It's a shame you can't justify this in your mind.

It escaped notice by your "experts" for many years.

Only now do you call it obvious.


What this actually shows is that nobody seemed to notice just how straight these columns really were until a "hobbyist" pointed it out.


Should have? Your experts missed it.


The Emperor has no clothes.

 

[DGM]

It escaped notice by your "experts" for many years.

Only now do you call it obvious.


What this actually shows is that nobody seemed to notice just how straight these columns really were until a "hobbyist" pointed it out.


Should have? Your experts missed it.


The Emperor has no clothes.

Why do you keep saying this? Most engineers are not in the habit of stating the obvious for the sake of the uninformed. You were not the first to notice this, you were the first to assume it was strange.

 

[Heiwa]

You have been shown where you are wrong and/or where you don't know what you are talking about. Heck, since I'm not one to even try to understand much of this, I even showed this thread to a couple friends over at the engineering part of my local university and THEY said you don't know what you are talking about. Every person on this forum whom I suspect does know what he talking about says you don't know what you are talking about.

I mean no disrespect, of course, but this worries me. As a layman I need to rely on experts, and if all the experts who disagree with you are wrong, If the consensus of experts world wide is wrong, if the building code changes occurring world wide because of the NIST's findings are wrong, then there is something seriously wrong with the engineering community, and we are in grave danger walking into any large building anywhere.

Don't you agree?

Details, please. What's wrong? We discuss what initiated the collapse and caused the alleged release of potential energy that later allegedly contributed to the global collapse. I show that the original structure was little stressed under compression (<30% yield) before inititation and that heat (500°C) will hardly affect it. But then I assume that something happens - buckling of all columns - and ask what kind of buckling; bending, twisting (torsion) or crumpling up (compression)? NIST ignores that.

And then there is the question if the 'buckling' resulted in release of potential energy (mass dropping down). It would appear that most energy is used only to 'buckle' the columns that deform a little ... and then should come to rest in a new state of equilibrium with deformed structural parts. This is what normally happens!

And NIST has apparently abandoned the complete column 'buckling' scenario and now suggests floors dropping down that initiated the global collapse.

But every video of the WTC1 collapse clearly shows that the roof drops considerably before anything serious happens at the initiation zone - where the floors are supposed to have dropped as the visible columns there are intact. After that all is hidden by smoke and dust.

Anyway, I also show that potential energy of a mass above cannot exceed the strain energy of the structure; another reason why global collapse will not ensue for the original NIST conclusion.

It is very disturbing that no pieces of the structure of the initiation zone are available for serious forensic examination to establish the initiation.

 

[Major_Tom]

Myriad notes:

"They could not match specific columns to specific as-built positions, for reasons they explained,

Is this from NIST 1-3c ?

I'm not seeing many reasons. Can you please indicate to what section and pages you are referring?

Why do you keep saying this? Most engineers are not in the habit of stating the obvious for the sake of the uninformed.

So NIST knew and didn't think it was important to mention? Bazant knew?

???


I couldn't be the first person to notice. You'd have to be blind not to notice.

 

[Major_Tom]

Einstein notes of samples of structural parts from the collapse initiation zones:

Such evidence can not reasonably be expected to exist,

??? Dustified?


Dave follows with:

Looking at the core columns, NIST's modelling predicts serious damage to a proportion of these also


If you are an investigative body, why theorize when you have access to the crime scene and the structural members being discussed?


Why are we "guessing" collapse initiation 6 years later when both core and perimeter sections contained all the information we needed?

 

[uk_dave]

So NIST knew and didn't think it was important to mention? Bazant knew?

What? That the core columns failed at their welds?

Maybe they should have produced a 'janet and john' version of their report.

Or, more in keeping with the 'truth' movement, produced 500 5 minute videos and posted them on youtube.

 

[Furcifer]

Why are we "guessing" collapse initiation 6 years later when both core and perimeter sections contained all the information we needed?

That's a bold statement after the fact. I find it fascinating that the truth movement puts their faith in the notion that the evidence of conspiracy could easily be found in information that cannot possibly be obtained. It's always about theorizing about what's not there, instead of focussing on what is there. No offence, but a statement such as the one above clearly shows you will never be satisfied Major Tom. No matter how much you are shown and explained you will always fall back on this arguement because in your eyes it's so simple. It's a symptom of woo many on this forum have seen over and over.

To answer your question, we are guessing collapse initiation because it is an impossible question to answer with the given information unless you are willing to accept the fact that it was caused by the impact of two jets hijacked by terrorists and flown into the buildings.