I need all debunkers I can get!

[twinstead]

Originally Posted by Heiwa

You are a genious. Thanks a lot. Nobel prize coming up!

Just like the Pulitzer Prize that awaits the journalist who uncovers the big 911 inside job.

Have you contacted a media outlet, anywhere in the world, with your slam-dunk evidence of an inside job?

[WilliamSeger]

Originally Posted by Heiwa

So NIST suggests that the WTC1 top part tilted before collapse ensued and that the videos showing the mast dropping first is some sort of illusion - due to the tilting of the roof.
But if the top part tilted - why isn't the mast tilting? It is upright on all videos from all directions.

Actually, you should take your own advice and look more closely, and at more videos. I have yet to see a single video that really shows the antenna dropping first. Every one that I've seen and looked at frame by frame shows the antenna and the top of the roof moving downward in exactly the same frame. But what I have seen is several versions of "truther analysis" that take two frame grabs from videos shot from the north side and use pixel counts to show that the antenna appears to have fallen farther than the roof. But that doesn't mean it started falling first -- that's just slopply thinking, and it's particularly stupid to claim that when the very same videos show the antenna and the roof starting to move in the very same frames. The simple explanation that's eluding you is that the top of the entire tower is tilting southward, away from the cameras on the north side. Are you familiar with the concept of perspective?

Furthermore, when you say the antenna is "upright on all videos from all directions," you're simply proving that you haven't really looked at very many videos, and apparently not a single one that wasn't shot from the north side.

My advice to you -- which I'm sure you'll ignore, but I'll offer it anyway -- is that you need to start over and learn more about what happened before you set out to impress the world with your opinions about how and why it happened.

[Heiwa]

So the WTC1 mast is either tilting straight away from or straight towards the cameras on all videos and that it's why we don't see the tilting of the mast - even if NIST sees the tilting of the roof? When records from east and west vantage points were viewed, it was apparent that the building section above the impact area tilted to the south as the building collapsed." (NIST 2005) Sounds strange. Or are you quoting from WTC2?

Because if the roof - or for that matter the whole mass above - is tilting to the south, we must assume that the whole south wall (not very hot) has buckled - 59 perimeter columns - and I cannot see that. But let's assume that it happen about 50 meters below the roof at floor 94.

The stresses in these wall columns are very low - 22.5% of yield stress - and it is a mystery that all 59 are suddenly buckling. Where did the energy come from to raise the stresses so that alleged buckling failure could occur? From the potential energy released? Too small! The mass has hardly shifted at all. But let's forget that.

It means that the center of gravity of the mass above has shifted sideways and that the south wall above the buckled wall is outside of the south wall below. What would you expect to happen then?

For once I would expect the mast to fall sideways towards south. On at least one video. Otherwise the tilting as suggested by NIST of WTC1 cannot be correct. And then I would assume that the south wall above the rupture zone would continue to tilt to the south and pull the mass above further south ... etc. Not that what appears to be an explosion occuring inside blowing floors 94-96 to pieces throwing the walls >60 meters sideways and the floors upwards. That is not how a global collapse (downwards) starts!

Read my childrens piece once again! http://heiwaco.tripod.com/nist.htm

[Mancman]

Originally Posted by Heiwa

So the WTC1 mast is either tilting straight away from or straight towards the cameras on all videos and that it's why we don't see the tilting of the mast - even if NIST sees the tilting of the roof? When records from east and west vantage points were viewed, it was apparent that the building section above the impact area tilted to the south as the building collapsed." (NIST 2005) Sounds strange. Or are you quoting from WTC2?

Because if the roof - or for that matter the whole mass above - is tilting to the south, we must assume that the whole south wall (not very hot) has buckled - 59 perimeter columns - and I cannot see that. But let's assume that it happen about 50 meters below the roof at floor 94.

The stresses in these wall columns are very low - 22.5% of yield stress - and it is a mystery that all 59 are suddenly buckling. Where did the energy come from to raise the stresses so that alleged buckling failure could occur? From the potential energy released? Too small! The mass has hardly shifted at all. But let's forget that.

It means that the center of gravity of the mass above has shifted sideways and that the south wall above the buckled wall is outside of the south wall below. What would you expect to happen then?

For once I would expect the mast to fall sideways towards south. On at least one video. Otherwise the tilting as suggested by NIST of WTC1 cannot be correct. And then I would assume that the south wall above the rupture zone would continue to tilt to the south and pull the mass above further south ... etc. Not that what appears to be an explosion occuring inside blowing floors 94-96 to pieces throwing the walls >60 meters sideways and the floors upwards. That is not how a global collapse (downwards) starts!

Read my childrens piece once again! http://heiwaco.tripod.com/nist.htm

What you personally see happening is irrelevant to reality. The south wall was burning for the entire 102 minute event. The walls were bowing inwards as much as 5 feet! It's obvious that the south wall unloaded and initiated collapse, just as the east wall of WTC2 did.

WTC1 South Face:


Oh, and here's the antenna leaning.

[Kage]

See, this is what I was talking about. Clear evidence regarding your claims about the mast. Sadly, it does not support what you describe. Why does everyone else see one thing and you see something entirely different? Does this make you feel special?

SN Kage, USN

[WilliamSeger]

Originally Posted by Heiwa

So the WTC1 mast is either tilting straight away from or straight towards the cameras on all videos and that it's why we don't see the tilting of the mast - even if NIST sees the tilting of the roof? When records from east and west vantage points were viewed, it was apparent that the building section above the impact area tilted to the south as the building collapsed." (NIST 2005) Sounds strange. Or are you quoting from WTC2?

Ever heard the term "invincible ignorance?" Apparently, I wasn't able to shame you into looking at this stuff a little more carefully before blathering on. All videos from the side that show the antenna at all show the antenna leaning southward. In many of them, it's hard to tell what the roof is doing at the same time because of the smoke, but here's one from the northeast that does show the northwest corner of the roof clearly:

http://www.studyof911.com/video/file...coll_NE_01.wmv

And here's an enlarged and slowed-down animation of the first few frames of the collapse, clearly showing that the northwest corner starts moving at exactly the same time as the antenna:



And as I said, despite your preference for spewing more ignorance instead of taking another look, even the videos from the north that don't show the tilt do show that corner starting to move at the same time as the antenna:

Originally Posted by Heiwa

Because if the roof - or for that matter the whole mass above - is tilting to the south, we must assume that the whole south wall (not very hot) has buckled - 59 perimeter columns - and I cannot see that.

And I think we've established that you haven't looked very hard, either. The fuzziness of your thinking here is in assuming that all 59 perimeter columns had to fail at exactly the same instance. Try to imagine, instead, removing the columns one at a time over a period of many minutes. Each time you remove a column, its load gets transferred to adjacent columns. Eventually, you get to the point where all the load is being carried by very few columns, yet the building is still standing. Now keep removing them. If you don't think that catastrophic buckling of those last few columns could then happen very suddenly, with very little resistance to the falling section, then you simply don't know enough about the subject to discuss it intelligently. The columns weren't removed, of course, but this is a much closer approximation to what actually happened, as more and more columns slowly bowed inward several feet, than your speculations about the implausibility of 59 columns failing "simultaneously."

Originally Posted by Heiwa

It means that the center of gravity of the mass above has shifted sideways and that the south wall above the buckled wall is outside of the south wall below. What would you expect to happen then?

What I would expect to happen as the top section began to tilt is that the falling side would be trying to lift the opposite side up, using the core columns and a few side perimeter columns as a fulcrum, so all of the load of the top section would then be on those columns. I would also expect that the tilting would move the center of mass toward the failed side, so the load would not be equally distributed on those columns, either; it would be heavier on that side of the core than it was on the opposite side of the core -- a combined effect that progressed farther and father toward the failed side as the tilt progressed. Since the core was designed only as a gravity frame, with a standard 1.67 factor of safety, I would not expect the core columns on that side and the few perimeter columns involved to withstand both the overloading and the bending (since bending would reduce their carrying capacity, in addition to any heat effects from the fire). So, I would expect those columns to fail next, quickly followed by the failure of the remaining core columns (for the same reasons), quickly followed by the failure of the remaining perimeter columns. In short, "progressive horizontal failure."

Oddly enough, what I would expect to happen seems to be exactly what did happen. On the other hand, you seem to be starting from a very fuzzy understanding of what happened, and then expecting people to be mystified (but impressed) with your own inability to explain why it happened.

Originally Posted by Heiwa

For once I would expect the mast to fall sideways towards south. On at least one video. Otherwise the tilting as suggested by NIST of WTC1 cannot be correct. And then I would assume that the south wall above the rupture zone would continue to tilt to the south and pull the mass above further south ... etc.

Once the last perimeter columns failed and the entire top started down, that top section was actually trying to rotate around it's center of mass, with very little southward inertia having developed during the initial tilting. The last views of the antenna show that the top was still rotating after the total collapse began, and the center of mass did continue southward somewhat, but with the building being over 200 feet wide, the center of mass never got very close to the edge of the building before the entire top had been destroyed.

Originally Posted by Heiwa

Not that what appears to be an explosion occuring inside blowing floors 94-96 to pieces throwing the walls >60 meters sideways and the floors upwards. That is not how a global collapse (downwards) starts!

It doesn't look like an "explosion" to me -- certainly not high explosives like TNT or RDX. The characteristic of those explosives is that a cloud of smoke expands very rapidly (because it's the high velocity of the pressure wave that makes those explosives destructive), and which then slows down. What we see in the collapse is a cloud of smoke and flames exiting the building at nowhere near the velocity of explosives, and then speeding up -- exactly what we would expect if it's being driven by air being forced out of the building by the collapse.

Originally Posted by Heiwa

Read my childrens piece once again! http://heiwaco.tripod.com/nist.htm

No thanks; all it takes is a few paragraphs to realize that your "childres piece" is based on sloppy research and fuzzy thinking. Apparently, that doesn't bother you at all. If you're going to write fantasies for children, I suggest sticking to magical bunnies and talking trains, since kids outgrow that sort of nonsense. The paranoid conspiracy theories are much harder to shake, and they're poisonous to rational thinking. You are spreading BS.

[Heiwa]

Originally Posted by WilliamSeger

The fuzziness of your thinking here is in assuming that all 59 perimeter columns had to fail at exactly the same instance. Try to imagine, instead, removing the columns one at a time over a period of many minutes. Each time you remove a column, its load gets transferred to adjacent columns. Eventually, you get to the point where all the load is being carried by very few columns, yet the building is still standing. Now keep removing them. If you don't think that catastrophic buckling of those last few columns could then happen very suddenly, with very little resistance to the falling section, then you simply don't know enough about the subject to discuss it intelligently. The columns weren't removed, of course, but this is a much closer approximation to what actually happened, as more and more columns slowly bowed inward several feet, than your speculations about the implausibility of 59 columns failing "simultaneously."

...

Once the last perimeter columns failed and the entire top started down, that top section was actually trying to rotate around it's center of mass, with very little southward inertia having developed during the initial tilting. The last views of the antenna show that the top was still rotating after the total collapse began, and the center of mass did continue southward somewhat, but with the building being over 200 feet wide, the center of mass never got very close to the edge of the building before the entire top had been destroyed.

If you read my article you find that the compressive stress in the perimeter wall columns is 22.5% of yield. None of the columns are heated >500°C and will therefore not lose any strength to start buckling = being 'removed' one a time = transferring the load to an adjacent column.

Or do you suggest that the whole south wall was pulled inwards by the floors that in turn were pulled down by the core that had lost its support due some local collapse? The latter I doubt very much because the bolted floor connections to the core columns will shear off first.

And why would the entire top suddenly be destroyed. In a few seconds! It seems, in fact, that the entire top is suddenly destroyed ... and then the whole mass above is in pieces and its mass cannot extert any load on the structure below.

In my view the energy to destroy the entire top cannot have been its own inherent potential energy. It is as simple as that. It is to much strain energy built into the top - 1000's of spandrels, 1000's of floor bolts and plenty of columns.

Imagine that the 'entire top' rests on the ground (and not on the 94th floor) and that the 94 th floor becomes the 'ground floor'.

Start removing the wall columns at the new ground floor until the top starts to tilt. What happens then? Does the 'entire top' suddenly destroy itself? In one second?

OK, assume it does! What happens to the ground?

[Jono]

Originally Posted by Heiwa

If you read my article you find that the compressive stress in the perimeter wall columns is 22.5% of yield. None of the columns are heated >500°C and will therefore not lose any strength to start buckling = being 'removed' one a time = transferring the load to an adjacent column.

As a past surface engineer and a current blacksmith/industrial smithy, I can tell you that if you heat steel up to 500 degrees Celsius, the integrity will have decreased notably. You used to forge swords at 500 degrees in the past, just imagine what might happen when such heated steel would've had tons and tons of weight ontop of it to support. It wasn't designed to keep its structural integrity at those temperatures, not even 500 degrees if we assume this is the case for arguments sake.

Steel looses some 25-35% of its integrity at 500 degrees Celsius, if I had to guess. Hence, it shouldn't be too hard to assume that this would be a disasterous state of integrity for any column or truss in any given skyscraper. The WTC's did suffer temperatures higher than so. You'd be surprized how hot it can get in the most common fires, not to mention large office fires.
I certainly accept the given reports of the temperatures in the WTC having reached a bit higher, since it is not uncommon for regular office fires sans any jet fuel to reach beyond 1000 degrees Celsius.

Quote:

Figure 1 shows the various nominal fire curves for comparison. It can be seen that, over a period of 2 hours, the hydrocarbon fire is the most severe followed by the standard fire, with the external fire being the least severe fire although the slow heating fire represents the lowest temperature up to 30 minutes. It is noteworthy that for standard and smouldering fires, the temperature continuously increases with increasing time. For the external fire, the temperature remains constant at 680°C after approximately 22 minutes. whereas for the hydrocarbon fires, the temperatures remain constant at 1100°C and 1120°C after approximate 40 minutes.

http://www.mace.manchester.ac.uk/project/research/structures/strucfire/Design/
performance/fireModelling/nominalFireCurves/default.htm

There you go.

Quote:

Or do you suggest that the whole south wall was pulled inwards by the floors that in turn were pulled down by the core that had lost its support due some local collapse? The latter I doubt very much because the bolted floor connections to the core columns will shear off first.

Well, the South Tower's collapse revealed that the core stood for a brief time after the floors and remaining structure had collapsed around, above and below it.
http://www.indybay.org/olduploads/wtc_core.mpg

[Newtons Bit]

Truther engineering is a laugh.

Originally Posted by Heiwa

If you read my article you find that the compressive stress in the perimeter wall columns is 22.5% of yield. None of the columns are heated >500°C and will therefore not lose any strength to start buckling = being 'removed' one a time = transferring the load to an adjacent column.

Wow, you can do averages and divide things. Impressive. Now run an analysis on what moments would be induced in the adjacent columns (of a column that failed) including a p-delta analysis. There is alot more going on than just compressive forces redistributing. The induced moments are significant and controlling, especially in a multiple column failure event.

Quote:

Or do you suggest that the whole south wall was pulled inwards by the floors that in turn were pulled down by the core that had lost its support due some local collapse? The latter I doubt very much because the bolted floor connections to the core columns will shear off first.

That's almost exactly the case. What do you think would happen when a core column would fail? What magical forces hold it up?

Quote:

In my view the energy to destroy the entire top cannot have been its own inherent potential energy. It is as simple as that. It is to much strain energy built into the top - 1000's of spandrels, 1000's of floor bolts and plenty of columns.

In my view, there is enough potential energy to overcome the strain energy. I even did the calculations to prove it, you can see them here: http://forums.randi.org/showthread.php?t=97584 I'd like to know if you even bothered to do calculations. Based on how you figured out what the yield stress in the columns will be after a failure, I can't imagine they would be anything accurate though.

Quote:

Imagine that the 'entire top' rests on the ground (and not on the 94th floor) and that the 94 th floor becomes the 'ground floor'.

Start removing the wall columns at the new ground floor until the top starts to tilt. What happens then? Does the 'entire top' suddenly destroy itself? In one second?

OK, assume it does! What happens to the ground?

The upper block would fail similarly to what happened on 9/11, assuming you also damaged some of the core columns. It wouldn't be exactly the same since the ground will be much stiffer than the upper stories of the lower block, but it is still going to look much the same. The edge columns of the 94th floor gives way, the upper floors tilt maybe a dozen degrees, this shears off the connections from the 94th to 95th floor and the whole thing comes down one story. The lower end of the columns on the 95th floor are now striking the debris of the 94th floor (some of it will still be mostly intact) and the ground at an angle producing vast bending moments in the first columns of the new upper block which bend and break without providing much resistance. The whole thing comes down. It doesn't magically keep tilting over about some fulcrum on the edge of the building and fall over like a tree, nor does it impact the ground/94th floor and stop without causing destruction on the floors above.

[Heiwa]

Originally Posted by WhiteLion

As a past surface engineer and a current blacksmith/industrial smithy, I can tell you that if you heat steel up to 500 degrees Celsius, the integrity will have decreased notably. You used to forge swords at 500 degrees in the past, just imagine what might happen when such heated steel would've had tons and tons of weight ontop of it to support. It wasn't designed to keep its structural integrity at those temperatures, not even 500 degrees if we assume this is the case for arguments sake.

Steel looses some 25-35% of its integrity at 500 degrees Celsius, if I had to guess. Hence, it shouldn't be too hard to assume that this would be a disasterous state of integrity for any column or truss in any given skyscraper. The WTC's did suffer temperatures higher than so. You'd be surprized how hot it can get in the most common fires, not to mention large office fires.
I certainly accept the given reports of the temperatures in the WTC having reached a bit higher, since it is not uncommon for regular office fires sans any jet fuel to reach beyond 1000 degrees Celsius.

There you go.

Of course you use heat to shape and assemble steel (I have done it for 40 years) but the heat up at floors 94-98 was much too little to affect the structure. Read the link in my article about it.

[Heiwa]

Originally Posted by Newtons Bit

What do you think would happen when a core column would fail? What magical forces hold it up?

Take core column no. 501 for example (as described in my article). Pretty heavy stuff! Cannot possibly buckle under any circumstances.

[Minadin]

Originally Posted by Heiwa

Take core column no. 501 for example (as described in my article). Pretty heavy stuff! Cannot possibly buckle under any circumstances.

Under any circumstances? Wow. We need to start duplicating this column design and start putting them in every building ever! Just think of the incredible things you could do with a column that can't fail, no matter what you ask it to do!

[Heiwa]

Originally Posted by Minadin

Under any circumstances? Wow. We need to start duplicating this column design and start putting them in every building ever! Just think of the incredible things you could do with a column that can't fail, no matter what you ask it to do!

Exactly - it never buckled. Ask then yourself how it failed!

[Jono]

Originally Posted by Heiwa

Of course you use heat to shape and assemble steel (I have done it for 40 years) but the heat up at floors 94-98 was much too little to affect the structure. Read the link in my article about it.

Much too little? You can clearly see structural failings and exterior buckling between the 94-98th floor.
By default, we can assume at least that from 94th floor and above were increasing it's dependant pressure on the directly subseqent lower floors, that's way too much of pressure for the convergent floors below to handle.

NISTNCSTAR1CollapseofTowers.pdf

[JimBenArm]

Originally Posted by Heiwa

Exactly - it never buckled. Ask then yourself how it failed!

I did and I answered "It wasn't explosives, fool! Get a life!". I'm not very nice to myself.

[funk de fino]

Originally Posted by Heiwa

Of course you use heat to shape and assemble steel (I have done it for 40 years) but the heat up at floors 94-98 was much too little to affect the structure. Read the link in my article about it.

What are the expected fire temps in an office/household fire?

[Heiwa]

Originally Posted by WhiteLion

Much too little? You can clearly see structural failings and exterior buckling between the 94-98th floor.
By default, we can assume at least that from 94th floor and above were increasing it's dependant pressure on the directly subseqent lower floors, that's way too much of pressure for the convergent floors below to handle.

NISTNCSTAR1CollapseofTowers.pdf

If you see any exterior column buckling, you see a miracle (or photoshop miracle). The exterior columns were much to strong and under too little compressive stress to buckle under the given circumstances.

Pls refer me to any NIST calculations showing how an exterior column would buckle, if they exist, and I will show you where they miscalculate.

I know that NIST in its FAQ appendix December 2007 suggests that 6 or 11 floors above fell down on floor 93 and overloaded it, but NIST does not explain how 4 200 or 7 700 bolts keeping these floors in place suddenly sheared off simultaneously. Another miracle?

[Newtons Bit]

Originally Posted by Heiwa

Take core column no. 501 for example (as described in my article). Pretty heavy stuff! Cannot possibly buckle under any circumstances.

Besides being absurd, that's not even what I asked. Assume a core column is severed from the plane impact. What magical forces hold the column above the severed line from falling?

[GStan]

From Heiwa's linked article....(my bolding)

"If this mass filled the total volume of the building above the initiation zone (190 000 m3), the uniform density would be 0.18 ton/m3 or the density of cotton! You could say that a big bale of cotton (mass above) rested on the structure below!"

Analogies are terrific.

[GStan]

Also from Heiwa's article....

"As soon as a floor sags, its concrete will break up in small pieces. There is no strain energy to resist bending and tension in concrete."

I'm no structural engineer and might be advised to sit out this debate, but a man has to have some fun. Why must the concrete break into 'small pieces'? As the trusses sag, the concrete will fracture somewhere along the point of the sagging arch and relieve the tension (leaving you with 2 huge pieces of concrete instead of just 1). Perhaps multiple fractures could occur depending upon the length of the truss and the amount of sagging. Once the tension has been removed, what force will continue to break up the concrete until it is in small pieces? And how does one define small pieces?

[twinstead]

Originally Posted by Heiwa

If you see any exterior column buckling, you see a miracle (or photoshop miracle). The exterior columns were much to strong and under too little compressive stress to buckle under the given circumstances.

Are you implying that the videos of the obvious buckling of the exterior columns in the last few minutes before the collapse are faked?

[Minadin]

Originally Posted by twinstead

Are you implying that the videos of the obvious buckling of the exterior columns in the last few minutes before the collapse are faked?

I think he's also implying that compression is the only force acting on the columns.

[twinstead]

Originally Posted by Minadin

I think he's also implying that compression is the only force acting on the columns.

Oh. It seemed to me that the obvious bowing occurred before the collapse started and any compression was available to act on them, but I'm no expert; I'm sure I barely know what compression means in this context

To me those images go a long way to explaining to this non expert what happened. We had a bird's-eye front row seat to the exact instant the building failed, and exactly at the location where it failed. Just inward bowing and the release of a massive portion of the building suddenly upon the part below the failure.

[GStan]

Originally Posted by twinstead

Oh. It seemed to me that the obvious bowing occurred before the collapse started and any compression was available to act on them, but I'm no expert; I'm sure I barely know what compression means in this context

To me those images go a long way to explaining to this non expert what happened. We had a bird's-eye front row seat to the exact instant the building failed, and exactly at the location where it failed. Just inward bowing and the release of a massive portion of the building suddenly upon the part below the failure.

Compression (i.e. gravity) is the vertical force of the building's weight pushing downward on the columns. The columns are also subjected to the lateral force of the heated, sagging floor trusses pulling the columns inward. As many have mentioned, this inward bowing is clearly visible in many photos and videos that captured the last few minutes before the collapse. It is patently absurd to believe that all of the images showing it are fake.

[twinstead]

Originally Posted by GStan

Compression (i.e. gravity) is the vertical force of the building's weight pushing downward on the columns. The columns are also subjected to the lateral force of the heated, sagging floor trusses pulling the columns inward. As many have mentioned, this inward bowing is clearly visible in many photos and videos that captured the last few minutes before the collapse. It is patently absurd to believe that all of the images showing it are fake.

Thanks. That made sense even to me.

So it all comes back to instead of him adjusting his theory in light of the visual evidence, he just claims the visual evidence is faked.

That's the first time I've ever seen a conspiracy theorist do that...

[Jono]

Originally Posted by Heiwa

If you see any exterior column buckling, you see a miracle (or photoshop miracle). The exterior columns were much to strong and under too little compressive stress to buckle under the given circumstances.

Pls refer me to any NIST calculations showing how an exterior column would buckle, if they exist, and I will show you where they miscalculate.

I know that NIST in its FAQ appendix December 2007 suggests that 6 or 11 floors above fell down on floor 93 and overloaded it, but NIST does not explain how 4 200 or 7 700 bolts keeping these floors in place suddenly sheared off simultaneously. Another miracle?

You seem quite ignorant of the very visible fact of exterior columns buckling, which you claim to be photoshopped if present. Why is that?

These generally provide a good read;
http://www.debunking911.com/sag.htm
http://www.debunking911.com/collapse.htm

Collapse Initiation

•The inward bowing of the East wall induced column instability, which progressed rapidly horizontally across the entire East face.

•The East wall unloaded and tried to redistribute the loads via the hat truss to the weakened core and via the spandrels to the adjacent North and South walls.

•The entire section of the building above the impact zone began tilting as a rigid block (all four faces; not only the bowed and buckled East face) to the East (about 7ºto 8º) and South (about 3ºto 4º) as column instability progressed rapidly from the East wall along the adjacent North and South walls. The building section above impact continued to rotate to the East as it began to fall downward, and rotated to at least 20 to 25 degrees.

•The change in potential energy due to downward movement of building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. Global collapse then ensued.

South Face of WTC1

(here you can see WTC1 suffering from fires as low as the 92nd floor up to the 112th floor, 113th-114th too if you look at the upper left corner.



http://wtc.nist.gov/pubs/Media_Publi...0505_final.pdf

NISTNCSTAR1CollapseofTowers.pdf

*NISTNCSTAR1-1.pdf More detail here: http://wtc.nist.gov/oct05NCSTAR1-1index.htm
*NISTNCSTAR1-2.pdf More detail here: http://wtc.nist.gov/oct05NCSTAR1-2index.htm
*NISTNCSTAR1-3.pdf More detail here: http://wtc.nist.gov/oct05NCSTAR1-3index.htm
*NISTNCSTAR1-4.pdf More detail here: http://wtc.nist.gov/oct05NCSTAR1-4index.htm
*NISTNCSTAR1-5.pdf More detail here: http://wtc.nist.gov/oct05NCSTAR1-5index.htm
*NISTNCSTAR1-6.pdf More detail here: http://wtc.nist.gov/oct05NCSTAR1-6index.htm
*NISTNCSTAR1-7.pdf More detail here: http://wtc.nist.gov/oct05NCSTAR1-7index.htm
*NISTNCSTAR1-8.pdf More detail here: http://wtc.nist.gov/oct05NCSTAR1-8index.htm

http://wtc.nist.gov/reports_october05.htm

[Heiwa]

Originally Posted by WhiteLion

You seem quite ignorant of the very visible fact of exterior columns buckling, which you claim to be photoshopped if present. Why is that?

•The inward bowing of the East wall induced column instability, which progressed rapidly horizontally across the entire East face.

•The East wall unloaded and tried to redistribute the loads via the hat truss to the weakened core and via the spandrels to the adjacent North and South walls.

•The entire section of the building above the impact zone began tilting as a rigid block (all four faces; not only the bowed and buckled East face) to the East (about 7ºto 8º) and South (about 3ºto 4º) as column instability progressed rapidly from the East wall along the adjacent North and South walls. The building section above impact continued to rotate to the East as it began to fall downward, and rotated to at least 20 to 25 degrees.

•The change in potential energy due to downward movement of building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. Global collapse then ensued.

Why do you suggest I am ignorant? No, I see no exterior columns buckling or instability. No, the East wall cannot bow inward ... it is too strong and not instable at all. The stresses in the East wall are very low.

The hat truss has nothing to do with this ... it is 15 floors above. Why would the East wall 'try' to use the roof for assistance ... to the core? The stresses in the East wall are still too low.

How can you suggest that the entire WTC1 building above the impact zone can tilt as a rigid block? It is not rigid at all. It is mostly air, there is a lot of SAND mixed with cement to form concrete in the floors (70% of the total remaining mass up there - most SAND/4-5% of the volume) and very little steel to support all this sand (1% of the volume). It is not rigid! The floors (mostly sand fixed by cement on a thin steel plate) is just bolted to the outer walls and inner columns.

The top part of WTC1 is of course the lightest part of the whole building.

So it is also the weakest part of WTC1 - the top. OK, 33 000 tons total but volume wise (a big volume) not heavier than a solid bale of cotton. And apart from air ... most sand in the floors .... and then some little steel in walls and columns.

I cannot see this bale of cotton/sand/steel rotate 20-25 degrees. And why would it do that? It is fixed to the structure below. Did the whole tower below rotate or was the top suddenly 100% free to rotate = not connected to the structure below. How could that happen?

And then this: The change in potential energy due to downward movement of building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. Global collapse then ensued.

What is global collapse? That a bale of cotton rotates? And falls down? Of course the strain energy of the strong structure below could absorb that little mass. The structure below was much stronger than the little weight up top.

So sorry. I do not follow. Read my simple observations at http://heiwaco.tripod.com/nist.htm again and look at the picture at the end of the article.

Simply speaking. Before any 'global collapse ensued' up top something else happened up above the initiation zone. The whole top part disintegrates. Sand in the floors is blown upwards, steel parts in the walls are thrown sideways - it is like a fountain of sand blowing UP. Like fire works? Look at the first 1/2 second of the 'collapse'. And, you need extra energy for that. Not little potential energy falling down in 1/2 second.

It is quite clear from the photo of the 'global collapse' taken one second after it started. Most of the mass above is blown 100 meters sideways in all directions and cannot put any strain on the structure below = no global collapse

The structure below? It is apparently disinitegrated by the same effects that happened above at the initiation zone. Whatever that could be?

[JimBenArm]

Originally Posted by Heiwa

Why do you suggest I am ignorant?

Must resist straight line...
Pulling me in...
Too strong... can't talk in complete sentences...

I can't let it pass!

Because you are! You prove it with every bit of nonsense you post here!

Ah, sweet release...

[twinstead]

Originally Posted by Heiwa

Why do you suggest I am ignorant? No, I see no exterior columns buckling or instability. No, the East wall cannot bow inward ... it is too strong and not instable at all. The stresses in the East wall are very low.

So you think the many videos of that exact thing happening are faked? You mean to tell me that you don't see any buckling or instability at all in this clip?

http://video.google.com/videoplay?do...85611926#1m10s

I'm no expert. Perhaps you can explain in small words what it is I am seeing in the above video, because to me it looks like some major bowing.

[Jono]

Originally Posted by Heiwa

Why do you suggest I am ignorant? No, I see no exterior columns buckling or instability. No, the East wall cannot bow inward ... it is too strong and not instable at all. The stresses in the East wall are very low.

But dear Heiwa, you need not tell me you didn't see exterior columns buckling, you need to tell me that you did since that is what I showed you in my post and links.

It is not negatable, you need to move on and give your alternative version of why they did buckle and what it ment for the buildings stability.

Quote:

How can you suggest that the entire WTC1 building above the impact zone can tilt as a rigid block? It is not rigid at all. It is mostly air, there is a lot of SAND mixed with cement to form concrete in the floors (70% of the total remaining mass up there - most SAND/4-5% of the volume) and very little steel to support all this sand (1% of the volume). It is not rigid! The floors (mostly sand fixed by cement on a thin steel plate) is just bolted to the outer walls and inner columns.

You're thinking volume-wise, not weight-wise.

Quote:

The top part of WTC1 is of course the lightest part of the whole building.

Erhm, everything from the 95th floor and above is in this case the tilting part, is this part the lightest part? Only if you compare this formention section with the rest of the building.
It sure wasn't lighter than say the 94th or 93rd floor.

Quote:

So it is also the weakest part of WTC1 - the top. OK, 33 000 tons total but volume wise (a big volume) not heavier than a solid bale of cotton. And apart from air ... most sand in the floors .... and then some little steel in walls and columns.

I cannot see this bale of cotton/sand/steel rotate 20-25 degrees. And why would it do that? It is fixed to the structure below. Did the whole tower below rotate or was the top suddenly 100% free to rotate = not connected to the structure below. How could that happen?

First you invision the aformentioned section to not be heavier than a solid bale of cotton of the same volume (remember this does not denote weight), then you proceed to argue about a "bale of cotton" and how this supposedly means the top must have been completely dismembered from the rest of the building??

You're not arguing on what I've written you nor on the links provided, that's for sure.

Here's the final report on the Twin Towers Collapse, by NIST.
http://wtc.nist.gov/NISTNCSTAR1CollapseofTowers.pdf
(The Account for WTC1 is on page 69, figures-pictures are listed before that, referenced in the given chapter).

Final Reports of the Federal Building and Fire Investigation of the World Trade Center Disaster.
In 0.7 seconds, 35 exterior columns were severed, whereas 2 were heavily damaged. 6 core columns were immedietaly severed, whereas 3 were heavily damaged.
43 of 47 core columns stripped of insulation on one or more floors.
Insulation stripped from trusses covering 60,000 ft2 of floor area.

While you're going through the NIST-reports, if you have the time I'd recommend you read the following paper at the same time;
Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions.

[Newtons Bit]

Originally Posted by Heiwa

I cannot see this bale of cotton/sand/steel rotate 20-25 degrees. And why would it do that? It is fixed to the structure below. Did the whole tower below rotate or was the top suddenly 100% free to rotate = not connected to the structure below. How could that happen?

And then this: The change in potential energy due to downward movement of building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. Global collapse then ensued.

What is global collapse? That a bale of cotton rotates? And falls down? Of course the strain energy of the strong structure below could absorb that little mass. The structure below was much stronger than the little weight up top.

Stop arguing from incredulity and using extremely poor and misleading analogies. I already did the math, the potential energy above can easily exceed the strain energy of the columns. The building will collapse and will not stop once started. Move on.

[Heiwa]

Originally Posted by Newtons Bit

Stop arguing from incredulity and using extremely poor and misleading analogies. I already did the math, the potential energy above can easily exceed the strain energy of the columns. The building will collapse and will not stop once started. Move on.

No, better to move back ... and check your calculations. As shown in my article being discussed (at the request of Lennart Hyland), it is shown that the compressive stresses in the relevant columns are very low ... even if some perimeter wall columns are missing and some core columns are assumed to be damaged (the tower still stands) and that heat cannot affect the still intact columns.

The stresses in the intact columns are still <40% of yield (assuming 500°C) and their slenderness ratio is/remains very small. This mean NO COLLAPSE can occur. The strain energy (strength) of the allegedly heated columns is still much bigger than any energy (or force) acting from above.

So no potential energy can be released.

But let's assume it does. Why would this energy then act on the structure below? The mass above - and its energy - is disconnected from the structure below! And regardless - the structure below is very strong and will just deflect any energy coming from above.

Any energy being released from above will of course take the path of least resistance below = through the air, and fall to the ground. This is what happens in every structure being overloaded and explains why no steel framed scyscraper suddenly collapses in 1000 000's of pieces.

Read again http://heiwaco.tripod.com/nist.htm . If you find any errors pls inform me.

[Gravy]

Originally Posted by Heiwa

So no potential energy can be released.

But let's assume it does. Why would this energy then act on the structure below? The mass above - and its energy - is disconnected from the structure below! And regardless - the structure below is very strong and will just deflect any energy coming from above.

Any energy being released from above will of course take the path of least resistance below = through the air, and fall to the ground. This is what happens in every structure being overloaded and explains why no steel framed scyscraper suddenly collapses in 1000 000's of pieces.

Absolutely astonishing.



Why did this progressive collapse proceed to the ground? Why did the mass above not know to transport itself laterally, using no energy, so that it could take the "path of least resistance" through the air? What a stupid mass!

Jeebus, I have to get away from this insanity.

[Pardalis]

"disconnected" is the operative word.

[T.A.M.]

and just as quick as I enter this thread, the insanity has driven me out...

TAM

[Corsair 115]

Originally Posted by Gravy

Absolutely astonishing.

Indeed. It would seem Heiwa is inventing entirely new laws of physics. Either that, or he is really bad at expressing his ideas clearly.

[Newtons Bit]

Originally Posted by Heiwa

No, better to move back ... and check your calculations. As shown in my article being discussed (at the request of Lennart Hyland), it is shown that the compressive stresses in the relevant columns are very low ... even if some perimeter wall columns are missing and some core columns are assumed to be damaged (the tower still stands) and that heat cannot affect the still intact columns.

I've asked you this already, what moments develop in a moment frame when one column in the frame is severed? What moments develop when a large row of columns are severed?

Quote:

The stresses in the intact columns are still <40% of yield (assuming 500°C) and their slenderness ratio is/remains very small. This mean NO COLLAPSE can occur. The strain energy (strength) of the allegedly heated columns is still much bigger than any energy (or force) acting from above.

Compressive stress is not the only stress in the columns. There is bending stress (in two different directions) as well as shear. These are all additive. From basic mechanics :

Pu/Pn + 8/9(Mux/Mnx + Muy/Mny) + Vu/Vn < 1

Or the column fails. Which it did. Now then, what other stresses are developed in the column? What forces do the severed core columns put on the exterior columns? You've shown a grossly inaccurate way of calculating compressive stress vs strength (Pu/Pn), now calculate Mux/Mnx, Muy/Mny, and Vu/Vn.

I've already calculated the kinetic energy of the collapse as 2105MJ, the strain energy to buckle, develop plastic hinges and ultimately sever the columns on an entire floor near the collapse floor as 171MJ. The collapse continues.

The upper block doesn't bounce off or go sliding off because it penetrates through the floor slabs of the lower block. The columns in the upper block are like a hundred knives slicing through the slab of the lower block.

Stop making up fake engineering and do something real. Compressive forces are not the only forces acting on the columns. Forces do not follow the path of least resistance. Electrical currents follow the path of least resistance. Forces are not electrical currents. Bodies in motion will continue in the direction they were moving in until acted upon by a force. The upper block will not fall directly on top of the columns of the lower block. The upper block falls on the floor slabs of the lower block. The slabs of the lower block cannot apply a force on the moving upper body that is large enough to deflect it.

It cannot be any more simple.

[A W Smith]

In auto accidents. Why don't cars morph around the utility poles they are hitting? I mean the energy path of least resistance is around the pole correct? so why doesn't the car just side-step the pole? AND you don't have that pesky gravity complication to contend with.

Heiwa my argument above makes just as much sense as yours. You have FAILED as an engineer.

[Heiwa]

Originally Posted by Newtons Bit

I've already calculated the kinetic energy of the collapse as 2105MJ, the strain energy to buckle, develop plastic hinges and ultimately sever the columns on an entire floor near the collapse floor as 171MJ. The collapse continues.

The upper block doesn't bounce off or go sliding off because it penetrates through the floor slabs of the lower block. The columns in the upper block are like a hundred knives slicing through the slab of the lower block.

I calculate the potential energy of the mass above (33 000 tons) after falling one floor (3.7 meters) at gravity (10 m/s²) as 339.17 kWh and that is not a lot. However, it assumes that all wall and core columns buckle/split simultaneously and that is not seen on any forensic records. The wall columns are not really heated at all (and do not buckle) and the core columns are according NIST not heated more than 500°C and can at that temperature not buckle due to mass above! They may compress and bulge, that's all. And it takes time. No potential energy will be released then!

No load of mass above can be transmitted from core to walls; the floor bolted connections the columns are too weak.

I doubt you have read my article.

[pomeroo]

Originally Posted by Heiwa

I calculate the potential energy of the mass above (33 000 tons) after falling one floor (3.7 meters) at gravity (10 m/s²) as 339.17 kWh and that is not a lot. However, it assumes that all wall and core columns buckle/split simultaneously and that is not seen on any forensic records. The wall columns are not really heated at all (and do not buckle) and the core columns are according NIST not heated more than 500°C and can at that temperature not buckle due to mass above! They may compress and bulge, that's all. And it takes time. No potential energy will be released then!

No load of mass above can be transmitted from core to walls; the floor bolted connections the columns are too weak.

I doubt you have read my article.

Why should we read the work of an incompetent? You have no idea how often your errors have been corrected on this forum.