9/11: The WTC Collapses

[psikeyhackr]

Come close? You can't scale the strength of materials... nor gravity. You can't make a scale model of the collapse. Not gonna work.

Who was the last person who told me that gravity could not be scaled?

It's called a centrifuge dude.

My model is not scaled for strength. It is deliberately as weak as possible. So if a larger and heavier model were designed to be AS WEAK AS POSSIBLE and still would not collapse then how could a real building with a FoS collapse?

But if my model was put into a centrifuge and its effective weight doubled then loops would be crushed under the static load because it is built as weak as possible. So it would have to be redesigned anyway to withstand the centrifuge. But then it would be stronger and more difficult to collapse under the dynamic load anyway so your argument is self defeating.

People who don't seem to actually understand the physics present absurd arguments.

psik

 

[Tony Szamboti]

I don't the the loads of the tower 1 is comparable precisely with other towers... as the the hat truss was up there and so forth. I am not aware of the weights given for the bracing or the hat truss steel by Bazant, or Urich or NIST... or the other unusual loads up top or the antenna(s). I am not asserting these were ignored... but they wouldn't be the same as other towers. No?

Does NIST produce a column by column report of the core or just their heat mappings? And how exactly were those mappings created?

I would like to see how the 73 K kips load was computed. Since you seem to know.. can you provide a reference?

This is how I see it from where I sit:

a. The precise amount of steel damaged in the cores in not known
b. The actual rating of each column is not known (all I've seen is that columns had higher ratings up top
c. The weights of the core bracing is not known (revealed)
d. The weights of the steel in the mech floors is not known (revealed)
e. The temps, location and duration of the fires is not knowable
f. The weight of the hat truss steel in not know (revealed)
g. All the loads: superimposed deal and live loads are not known (reveal) They appear as crude estimates though I could be wrong here. Greg's work is
very rough.

All the above seem to leave lots of doubt .. in my mind at least.

Actually, the loads from the antenna, hat truss, and difference between the mechanical floor at the top of WTC 1 and a typical floor are only a small percentage of the 12 story upper section load.

The NIST load of 73,143 kips on the columns between floors 98 and 99 is shown in NCSTAR 1-6D, p. 176, Table 4-7.

Some of the things you are claiming to be unknown are actually known, such as the core column types and yield strengths throughout the height of the towers. Others can be easily estimated or bounded from the information we have.

In my opinion Gregory Urich's wtc mass analysis work is not rough and it sounds like you are indulging yourself here with that comment.

What leaves a lot of doubt in my mind is how any natural process could cause the building to collapse across the entire 98th floor within about 0.25 seconds and then have at least two floors above it disintegrate while continuously accelerating.

 

[psikeyhackr]

In my opinion Gregory Urich's wtc mass analysis work is not rough and it sounds like you are indulging yourself here with that comment.

So why does Urich's steel distribution have this steady 13 ton increase down the building and the top 5 stories do not seem to show the weight of the hat truss?

psik

 

[Tony Szamboti]

So why does Urich's steel distribution have this steady 13 ton increase down the building and the top 5 stories do not seem to show the weight of the hat truss?

psik

Here are the masses of the top 12 stories and the roof of WTC 1 from Gregory Urich's analysis, starting with the roof, which he calls 111 and going down to floor 99.

(10e3 kg) Story

2,610.20 111
3,845.54 110
2,639.91 109
4,210.56 108
2,849.55 107
1,848.07 106
1,847.48 105
1,853.91 104
1,860.34 103
1,866.78 102
1,873.21 101
1,830.32 100
1,836.75 99

It would seem to me that the top 5 stories reflect the weight of the hat truss, antenna, and mechanical floor up there. So it sounds like you might have gone off half cocked here.

Of course, Urich had to interpolate the perimeter column weights at each story, as they weren't released publicly. However, the total weight was and an interpolation would be reasonable and it would certainly be somewhat accurate as it can't be any other way.

I have seen you moan and groan about Urich's analysis in the past and I can't understand why you would do that instead of welcoming what he did with what we have so far while continuing to clamor for the actual wall thicknesses and grades of the perimeter columns at each story, and the core beams and their connections to be released.

 

[psikeyhackr]

Of course, Urich had to interpolate the perimeter column weights at each story, as they weren't released publicly. However, the total weight was and an interpolation would be reasonable and it would certainly be somewhat accurate as it can't be any other way.

Well I don't understand why EVERYONE doesn't object to that not being released publicly.

The government seems to expect everyone to believe that airliners could destroy the buildings but they don't have to PROVE IT by at least supplying complete data.

psik

 

[phoenyx]

Of course, Urich had to interpolate the perimeter column weights at each story, as they weren't released publicly. However, the total weight was and an interpolation would be reasonable and it would certainly be somewhat accurate as it can't be any other way.

Well I don't understand why EVERYONE doesn't object to that not being released publicly.

The government seems to expect everyone to believe that airliners could destroy the buildings but they don't have to PROVE IT by at least supplying complete data.

I notice that Tony did say that he's fine with your desire to know the "actual wall thicknesses and grades of the perimeter columns at each story, and the core beams and their connections to be released", but it's been my impression for quite some time based on Tony's posts and other sources of information, that it's not truly necessary to have this additional data to realize that the WTC buildings couldn't have collapsed due to the jet impacts/fires/debris.

As to why they haven't come to the conclusion that Tony and others have come up with, I don't believe that it was due to a lack of enough data, it's that they didn't bother doing the analysis after the so called collapse initiation point.

 

[SanderO]

I notice that Tony did say that he's fine with your desire to know the "actual wall thicknesses and grades of the perimeter columns at each story, and the core beams and their connections to be released", but it's been my impression for quite some time based on Tony's posts and other sources of information, that it's not truly necessary to have this additional data to realize that the WTC buildings couldn't have collapsed due to the jet impacts/fires/debris.

As to why they haven't come to the conclusion that Tony and others have come up with, I don't believe that it was due to a lack of enough data, it's that they didn't bother doing the analysis after the so called collapse initiation point.

This is where I disagree with Tony and your reasoning here.

The structure at the top floors consisted of thousands of pieces of steel and tens of thousands of connections and probably a hundred thousand bolts and welds. We don't know the specs of all of these and they DO MATTER because there was a progressive de construction of the frame. You simply can't turn this into blocks of simplified calculations has Bazant, Szamboti and others have attempted. So I take exception with the method and their assumptions. An FEA would produce a more reliable result if all the inputs were there. But again without them it is garbage in = garbage out.

How do we solve this conundrum?

For those who conclude a structural collapse of the top was impossible and assert devices were used... they need to explain where the devices were placed. what sort they were, how much force they applied or heat if weakening was the mechanism... and most importantly they need to produce SOME evidence in the debris that aligns / supports these mechanisms. You cannot prove that the building's top can't collapse... based on few and in some cases wrong assumptions and then say ergo it was CD. That doesn't wash.

My position tries to use the observations, the movements, the data derived from it, the actual structural design and strategy used by the engineers and the principles of physics (thermodynamics and Euler and applied engineering....

"Bifurcation buckling[8][9] is sometimes called Euler buckling even when applied to structures other than Euler columns. As the applied load is increased by a small amount beyond the critical load, the structure deforms into a buckled configuration which is adjacent to the original configuration. For example, the Euler column pictured will start to bow when loaded slightly above its critical load, but will not suddenly collapse."

You will find not a single mention of Euler buckling in any of the 9/11 truth literature.

That's odd to say the least.

 

[Thoreau72]

Well I don't understand why EVERYONE doesn't object to that not being released publicly.

The government seems to expect everyone to believe that airliners could destroy the buildings but they don't have to PROVE IT by at least supplying complete data.

psik

The coverup is worse than the crime, and still going on today. Information and evidence has been suppressed and destroyed. Public dialogue is suppressed. The Official STory is made into movies, and repeated ad nauseam.

 

[shanners]

It sounds like you might enjoy this interview of Benjamin Chertoff's Popular Mechanics colleague Davin Coburn by Charles Goyette in 2006 about their 911 article

Charles Goyette's Popular Mechanics 9/11 Interview causes cancellation of later interviews.

Thanks for that, he really tears him to pieces.

 

[Enik]

and most importantly they need to produce SOME evidence in the debris that aligns / supports these mechanisms.

Would you know what these would look like if presented to you?

 

[Tony Szamboti]

This is where I disagree with Tony and your reasoning here.

The structure at the top floors consisted of thousands of pieces of steel and tens of thousands of connections and probably a hundred thousand bolts and welds. We don't know the specs of all of these and they DO MATTER because there was a progressive de construction of the frame. You simply can't turn this into blocks of simplified calculations has Bazant, Szamboti and others have attempted. So I take exception with the method and their assumptions. An FEA would produce a more reliable result if all the inputs were there. But again without them it is garbage in = garbage out. How do we solve this conundrum?

Simplifying assumptions are made everyday in engineering. The basis behind the simplifying assumptions for analyzing the WTC upper sections have been shown and demonstrated. You are just appealing to complexity here in an attempt to dismiss. It won't work.

For those who conclude a structural collapse of the top was impossible and assert devices were used... they need to explain where the devices were placed. what sort they were, how much force they applied or heat if weakening was the mechanism... and most importantly they need to produce SOME evidence in the debris that aligns / supports these mechanisms. You cannot prove that the building's top can't collapse... based on few and in some cases wrong assumptions and then say ergo it was CD. That doesn't wash.

To warrant a new investigation all that has to be done is to show the present official theory is non-explanatory. That has been done.

My position tries to use the observations, the movements, the data derived from it, the actual structural design and strategy used by the engineers and the principles of physics (thermodynamics and Euler and applied engineering....

"Bifurcation buckling[8][9] is sometimes called Euler buckling even when applied to structures other than Euler columns. As the applied load is increased by a small amount beyond the critical load, the structure deforms into a buckled configuration which is adjacent to the original configuration. For example, the Euler column pictured will start to bow when loaded slightly above its critical load, but will not suddenly collapse."

You will find not a single mention of Euler buckling in any of the 9/11 truth literature.

That's odd to say the least.

This isn't true. In my paper The Sustainability of the Controlled Demolition Hypothesis for the Destruction of the Twin Towers, which can be found on the Journal of 911 Studies or at the direct link here http://www.journalof911studies.com/...itionHypothesisForDestructionofTwinTowers.pdf, I talk a significant amount about buckling. It would actually be plastic buckling which would be involved with columns having the low slenderness ratio of those in the towers and it uses the Johnson parabola for calculation of it's onset. Pure Euler buckling is only for elastic buckling where slenderness ratios are over 100. The columns in the towers had slenderness ratios below 30.

 

[SanderO]

Simplifying assumptions are made everyday in engineering. The basis behind the simplifying assumptions for analyzing the WTC upper sections have been shown and demonstrated. You are just appealing to complexity here in an attempt to dismiss. It won't work.

To warrant a new investigation all that has to be done is to show the present official theory is non-explanatory. That has been done.


This isn't true. In my paper The Sustainability of the Controlled Demolition Hypothesis for the Destruction of the Twin Towers, which can be found on the Journal of 911 Studies or at the direct link here http://www.journalof911studies.com/...itionHypothesisForDestructionofTwinTowers.pdf, I talk a significant amount about buckling. It would actually be plastic buckling which would be involved with columns having the low slenderness ratio of those in the towers and it uses the Johnson parabola for calculation of it's onset. Pure Euler buckling is only for elastic buckling where slenderness ratios are over 100. The columns in the towers had slenderness ratios below 30.

Yes I am appealing to non reductionist thinking. The collapses were way too complex to reduce them the simplified blocks.

I agree that to show that the NIST report was wrong is sufficient to warrant a new investigation. No problem with that and several have caught NIST in their falsity (is that word?)

Some of the columns collapsed from EULER buckling (spire) when the bracing was stripped off leaving them with slenderness ratios of over 150...

any column which loses its bracing such as the twin tower core columns is hardly restrained at all by the connection to the column above an below... loss of three braces puts that column into a very precarious place.

 

[SanderO]

Would you know what these would look like if presented to you?

I think I can tell the difference between a column which was blasted apart from one which ripped free of the connection splices.

From the photos I have looked at... hundreds of them I don't see anything but ripped apart connections... welds, bolt withdrawals bent over plates and so forth.

But I have seen no examples of exploded steel. Perhaps you can provide a link to exploded steel (connections)?

 

[Thoreau72]

I think I can tell the difference between a column which was blasted apart from one which ripped free of the connection splices.

From the photos I have looked at... hundreds of them I don't see anything but ripped apart connections... welds, bolt withdrawals bent over plates and so forth.

But I have seen no examples of exploded steel. Perhaps you can provide a link to exploded steel (connections)?

What about sulfidated steel Sander? Did you come upon any of that in your wanderings through the evidence?

I did. Assuming you will actually admit that it existed, what do you make of it?

 

[SanderO]

What about sulfidated steel Sander? Did you come upon any of that in your wanderings through the evidence?

I did. Assuming you will actually admit that it existed, what do you make of it?

Yes I saw at least one steel WF section which showed what was determined to be sufidation. I have a few comments:

1. How come one steel wf beam and not a single column? Would weakened beam such as the one presented as sufidated cause one of the towers to colllapse? That one beam? If there were more... where are they?

2. Sulfidation is a chemical process. When was that piece of steel recovered? Where was it found? Which building did it come from and where was it in the frame? And most importunately how do we determine WHEN the sufidation occurred.... before and leading to the collapse??? or after attacked by heat and chemical soup under the pile?

This is very odd and needs to be explained and studied... but one sulfidated beam is certainly not proof of explosive controlled demolition.

 

[Tony Szamboti]

I think I can tell the difference between a column which was blasted apart from one which ripped free of the connection splices.

From the photos I have looked at... hundreds of them I don't see anything but ripped apart connections... welds, bolt withdrawals bent over plates and so forth.

But I have seen no examples of exploded steel. Perhaps you can provide a link to exploded steel (connections)?

Are you actually claiming that because you haven't seen photos of steel which may have had blast evidence that it is unlikely? You do realize that only certain people were permitted to do photography at the WTC collapse site and that the photos released are likely to have been censored. I would think it much more likely that we haven't seen many of the photos.

 

[SanderO]

Are you actually claiming that because you haven't seen photos of steel which may have had blast evidence that it is unlikely? You do realize that only certain people were permitted to do photography at the WTC collapse site and that the photos released are likely to have been censored. I would think it much more likely that we haven't seen many of the photos.

I am fully aware that I cannot not prove or disprove what I can't see. I simply said I haven't seen any visual evidence that I can point to that looks like exploded steel.

There are very odd things... the meteor, the eutectic steel, the horseshoe column to name a few. while can't claim to have seen all the debris...I don't think it was even photographed of logged... of the thousands of connections that I saw... not a one looked to my naive eyes as if it was anything other than being violently ripped apart.

The dumsfeld said:

"There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know."

 

[Knowledge=power]

"There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know."

Mindf***?

 

[phoenyx]

[Donald Rumsfeld once said:]
"There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know."

Not that I like Rumsfeld, but I actually think that was a pretty good line. Wikipedia goes into great depth on it here:
There are known knowns - Wikipedia, the free encyclopedia

 

[Tony Szamboti]

I am fully aware that I cannot not prove or disprove what I can't see. I simply said I haven't seen any visual evidence that I can point to that looks like exploded steel.

There are very odd things... the meteor, the eutectic steel, the horseshoe column to name a few. while can't claim to have seen all the debris...I don't think it was even photographed of logged... of the thousands of connections that I saw... not a one looked to my naive eyes as if it was anything other than being violently ripped apart.

The dumsfeld said:

"There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know."

What we do know about the collapse of WTC 1 is


- the central core collapsed first as indicated by the antenna drop of 8 to 10 feet before any movement of the exterior roofline.
- the central core pulled the exterior columns inward causing them to buckle and the exterior to drop with the central core.
- that a structure built to support several times the load above it cannot be collapsed by that load without a deceleration occurring to gain the required amplification.
- the upper section never decelerates through the measurable period of the fall, which is the first nine stories.

 

[SanderO]

Tony Szamboti

What we do know about the collapse of WTC 1 is


- the central core collapsed first as indicated by the antenna drop of 8 to 10 feet before any movement of the exterior roofline.

I aggree... don't know the precise distance


- the central core pulled the exterior columns inward causing them to buckle and the exterior to drop with the central core.

Pull in and buckle sounds contradictory... Pull in sounds like bending them... buckle sounds like excessive axial load. One or the other... can't be both at the same time.


- that a structure built to support several times the load above it cannot be collapsed by that load without a deceleration occurring to gain the required amplification.

True... there is always deceleration when there is collisions. We can't see any collisions per se... they were hidden They were spread out over time and the facade to which they may still have been attached (ASSUMPTION here) would show a smoothed motion... However others claim to have measured a series of small jolts...decelerations.... I don't know for sure.


- the upper section never decelerates through the measurable period of the fall, which is the first nine stories.

Was it free fall? if not what was slowing it down... friction?

 

[Enik]

… An FEA would produce a more reliable result if all the inputs were there. But again without them it is garbage in = garbage out.

This is such an illogical statement, eventually made by all debunkers that have little understanding of FEA. Maybe you can show me an FEA outside of the WTC realm that supports garbage in = garbage out.

Other absurd statements include (but are not limited to): One has to know all of the details of each and every bolt and accountability of all the steel however, one cannot know everything so therefore one knows nothing. Or there is so much to input that no computer could handle it. Or it would take years for the most advance computer on earth to crunch all of the numbers and they would still be wrong since we do not know what was going on inside the towers.

… My position tries to use the observations, the movements, the data derived from it, the actual structural design and strategy used by the engineers and the principles of physics (thermodynamics and Euler and applied engineering....

Your position is exclusive to yourself. You even reject the NIST FEA model that supports most of your theory because it does not explain the bow in of the perimeter columns.

…In both cases most truthers have botched the observations, work with cartoon conceptions which don't represent the destruction...such as falling blocks... and mis apply Newton and ignore Euler's laws of mechanics. They rely heavily on mis read photos, no data taken from them in most cases.... and anecdotal statements.

I do not see a difference with this statement and your theory. Maybe you can point me to some specific examples.

I think I can tell the difference between a column which was blasted apart from one which ripped free of the connection splices.

Are you speaking from personnel experience or from the photographs that were approved for release to the public?

 

[Thoreau72]

Yes I saw at least one steel WF section which showed what was determined to be sufidation. I have a few comments:

1. How come one steel wf beam and not a single column? Would weakened beam such as the one presented as sufidated cause one of the towers to colllapse? That one beam? If there were more... where are they?

2. Sulfidation is a chemical process. When was that piece of steel recovered? Where was it found? Which building did it come from and where was it in the frame? And most importunately how do we determine WHEN the sufidation occurred.... before and leading to the collapse??? or after attacked by heat and chemical soup under the pile?

This is very odd and needs to be explained and studied... but one sulfidated beam is certainly not proof of explosive controlled demolition.

Good questions. Do you suppose they might have been answered if so much of the steel had not been shipped off to China so quickly? Do you suppose that proper forensic examination might have revealed the sulfidation to be widespread?

Does the presence of sulfidated steel somehow suggest the presence of a sulfurated compound such as thermate?

 

[SanderO]

This is such an illogical statement, eventually made by all debunkers that have little understanding of FEA. Maybe you can show me an FEA outside of the WTC realm that supports garbage in = garbage out.

Other absurd statements include (but are not limited to): One has to know all of the details of each and every bolt and accountability of all the steel however, one cannot know everything so therefore one knows nothing. Or there is so much to input that no computer could handle it. Or it would take years for the most advance computer on earth to crunch all of the numbers and they would still be wrong since we do not know what was going on inside the towers.

Your position is exclusive to yourself. You even reject the NIST FEA model that supports most of your theory because it does not explain the bow in of the perimeter columns.

I do not see a difference with this statement and your theory. Maybe you can point me to some specific examples.

Are you speaking from personnel experience or from the photographs that were approved for release to the public?

Enik,

Chill out please. I don't expect that every single bolt, weld and connection needs to be included in an FEA. I do think that some of the main connections need to be examined in more detail than they seem to have been. I did see some testimony, recently, which was given in 2002 by the ASCE before congress about their concern about connections related to the frame coming apart. This was supposed to be looked into by formal technical investigation. I am unaware of any formal or informal studies of the connections in any of the towers in any of the locations of the frame. If you know of such studies please direct me to them.

But studies with limited data.. reductionist... will produce less reliable results and may miss important details. Garbage in = garbage out may be too harsh a statement... but one cannot look at the destruction of a frame with thousands of elements as a block.

I consider FEA a valuable tool and don't expect to 1:1 model of the real world and accept the limitations of models.
.
I only speak for myself and support the ROOSD conception of the collapse of the twins. I don't profess to know what caused the tops to drop... It seems to me to be a loss of axial strength of the core columns. What happens next is anyone's guess. I assume that the insides rapidly came apart leaving the facade with some floors trusses and parts of slabs hanging from it. I have no proof to support this assumption. No one as far as I can tell can know or prove what was happening inside the top once it began to drop.

As the antenna in WTC 1 moved down INTO the top before the top began to move it is sage to assume that there was significant destruction to the central part of the hat truss and the core below that. This assumption is based on the notion that the central columns below the antenna could not support the ~360 ton concentrated antenna load without them being redistributed by the hat truss. But again we can't know if the central columns below the crown of the hat truss (antenna) failed first... and the hat truss then failed was destroyed in the center enabling the antenna drop.. It's a reasonably good assumption to make that with the column destruction of the center of row 500 and the likely loss of strength to row 600.. the failure of the center of 700 was next in line and might lead to the antenna drop. All assumptions of course.

I, and others have found that the NIST got several key things wrong and so I find their results would be in question.

I do have a issue with the term *bow in*. First it does not specify which columns of the facade moved inward.. as it wasn't the entire facade. Second the movement inward could be from a pull as NIST tries to claim... or a buckling from excessive axial loads as I think is another explanation. How do you get the trusses to sag from heat weakening... the floor no cracking and destroy the composite AND have the strength to pull the facade inward and not fail the heat weakened bolts? The Siewart study reveals there were various truss seat failures... broken off, bent up legs and bent down legs. all of which came from different force vectors I would assume.

Point to you of specific examples of what?

I am not pleased at all by the manner in which the NIST has kept information (evidence) from the public. Clearly they are self serving and will not release evidence which shows their conclusions were bogus. People are like that... organizations are like that. NIST seems to have had an agenda to NOT study the unusual structural design decisions employed in all three towers which MAY have contributed to the complete collapse and cast some responsibility over to the engineers, designers and developers. This happens to be something I am alone in suggesting.

 

[SanderO]

Good questions. Do you suppose they might have been answered if so much of the steel had not been shipped off to China so quickly? Do you suppose that proper forensic examination might have revealed the sulfidation to be widespread?

Does the presence of sulfidated steel somehow suggest the presence of a sulfurated compound such as thermate?

While there may have been more sulfidated steel spirited away... than the one example seen... there are no reports of anyone seeing lots of this stuff... and I've not see it in the many post collapse debris photos I've looked at. Again not proof that it's was not there.. but I've not see it nor heard of more of it.

The more interesting question is what, if anything can be drawn form this finding? I am not a chemist...but sulfidation is caused by SO2 and how that was released to attack the steel is the mystery. Could leaking UPS batteries play role? I have no way of knowing. It seems that various theories can be tested to rule out substances in the building. I don't know that this was pursued.

The issue of a thermate or themite attack of the steel raises the question... what might have been this been used? Columns? connections, bracing? One would need to do more than recognize that this stuff eats through steel... but how would it be used to take the towers down.