WTC collapses - Layman's terms again

[Myriad]

When any failed part is displaced downwards due to gravity it releases energy. In local failures, parts still attached to other parts, that energy is normally consumed causing local deformation of the failed part! You agree?

By definition, if the failure is local ("local" and "global" describe the results of a failure, not the nature of the failure mechanism itself), then the falling parts must come to rest, so their kinetic energy must be converted into heat (via mechanical deformation) and/or other mechanisms (such as coupling to dispersive fluid motion). So, I agree by definition.

Of course, if a big loose weight on a failed part starts to drop free fall there is energy involved/released ... but then we have to analyse that;

Here's where you go wrong. It doesn't have to be free fall for energy to be released. You jump from "local failure" (moving parts must come to rest) to "free fall" (moving parts must be "loose") as if there were no other possibilities in between. That is a classic false dichotomy fallacy.

Perhaps you might try to think of a mechanism in which the fall of a weight in a gravitational field provides a continuous source of energy over a period of time (that is to say, power), and yet the weight is in no way "loose" and it never free falls. If you're stumped, I'll post a picture of one later.

Everything else, i.e. the structural parts, were connected to one another. Nothing free falls!

So what?

Any fall in a downward direction in a gravitational field releases GPE. It doesn't have to be a free fall.

Sorry - you are 100% wrong in your analysis. Try again. I always look forward to your comments.

I'll leave it to others to judge who's right and who's wrong.

Your knowledge of ship collisions is not sufficient rationale to conclude that you are right and all other engineers and physicists who have weighed in here are wrong. That's because ship collisions have a tiny fraction of the available energy of the building collapses, and thus are an extremely poor model, far more different from the actual process of the tower collapses than Bazant's model whose inaccuracy you criticize.

Respectfully,
Myriad

 

[Heiwa]

How about the resistance of the floor structure to the gravitational acceleration of the top mass. You told me before you don't deal with this because you like to keep it simple. Impress us with your calculations!

The floor is bolted to the columns. Any weight on (the top mass) and of the floor itself (i.e. mass of the floor itself) is transmitted only via the floor truss to the bolt and to the column as a shear force. The shear force is evidently produced by gravity. As no displacements (except elastic ones) take place under normal circumstances, there is no release of any energy. The resistance of the floor is quite good ... for furniture and people on it.

BTW - the shear force also produce bending in the floor truss, but the bending moment in the truss at the bolt is zero so no bending is transmitted to the column.

Thus - the top mass on a floor is normally transmitted to the columns via the bolts and that's how the floor resists the top mass.

If the top mass is very big, the bolt may shear off or the floor truss will fail locally due bending. In either case the column will never be damaged by an excessive weight on the floor.

That was an easy one. I think I explained it in one of my articles or in a message at JREF before. Actually most questions you ask are already answered there. Pls read my articles.

 

[DGM]

The floor is bolted to the columns. Any weight on (the top mass) and of the floor itself (i.e. mass of the floor itself) is transmitted only via the floor truss to the bolt and to the column as a shear force. The shear force is evidently produced by gravity. As no displacements (except elastic ones) take place under normal circumstances, there is no release of any energy. The resistance of the floor is quite good ... for furniture and people on it.

BTW - the shear force also produce bending in the floor truss, but the bending moment in the truss at the bolt is zero so no bending is transmitted to the column.

Thus - the top mass on a floor is normally transmitted to the columns via the bolts and that's how the floor resists the top mass.

If the top mass is very big, the bolt may shear off or the floor truss will fail locally due bending. In either case the column will never be damaged by an excessive weight on the floor.

That was an easy one. I think I explained it in one of my articles or in a message at JREF before. Actually most questions you ask are already answered there. Pls read my articles.

So I take it you can't answer the question. You can't explain your "gut feeling" as to how the collapse would be arrested. Keep trying to convince children because us adults have exposed you as a hopeless fraud.

 

[Heiwa]

By definition, if the failure is local ("local" and "global" describe the results of a failure, not the nature of the failure mechanism itself), then the falling parts must come to rest, so their kinetic energy must be converted into heat (via mechanical deformation) and/or other mechanisms (such as coupling to dispersive fluid motion). So, I agree by definition.

Here's where you go wrong. It doesn't have to be free fall for energy to be released. You jump from "local failure" (moving parts must come to rest) to "free fall" (moving parts must be "loose") as if there were no other possibilities in between. That is a classic false dichotomy fallacy.

Perhaps you might try to think of a mechanism in which the fall of a weight in a gravitational field provides a continuous source of energy over a period of time (that is to say, power), and yet the weight is in no way "loose" and it never free falls. If you're stumped, I'll post a picture of one later.

So what?

Any fall in a downward direction in a gravitational field releases GPE. It doesn't have to be a free fall.

I'll leave it to others to judge who's right and who's wrong.

Your knowledge of ship collisions is not sufficient rationale to conclude that you are right and all other engineers and physicists who have weighed in here are wrong. That's because ship collisions have a tiny fraction of the available energy of the building collapses, and thus are an extremely poor model, far more different from the actual process of the tower collapses than Bazant's model whose inaccuracy you criticize.

Respectfully,
Myriad

Myriad. Pls differentiate between gravity Force F (Newton) and gravity (potential) Energy E (Joule).

Gravity Forces are everywhere. Gravity Energy is only produced when a gravity Force is displaced a certain distance d (m= meter), i.e. E = F times d (because Joule = Newtonmeter).

Everybody looking at the WTC 1 collapse should keep trace of all the forces F and their displacements d. KISS.

I know very well that a displacement does not need to be free fall. Free fall is just assumed by various conspiracy theorists to initiate the WTC 1 destruction; F = the force acting on the whole upper block only, displacement d = one storey, E = F times d, that is applied on the lower structure as one impact! That is too simple. It is neither scientific or engineering.

In my analysis there are many forces F that are moving around (no displacements), causing local failures and deformations here and there and, I point it out, some local, small free falls of minor parts that have failed and are not initially resisted, but that in the end all the local failures of WTC 1 are arrested. The gravitational energies released at the various steps due local failures are 100% consumed as local deformation (heat) and friction between loose parts (also heat) = no global collapses. Only conspiracy theorists believe otherwise.

You should be happy about my clarifications. It is good news. The main reason why steel towers do not suddenly collapse only due to gravity.

 

[Newtons Bit]

I don't typically respond to Heiwa's drivel, but this post is full of such idiotic things that I'm going to take apart his post a bit and show where he doesn't have a freaking clue as to how buildings are designed.

The floor is bolted to the columns. Any weight on (the top mass) and of the floor itself (i.e. mass of the floor itself) is transmitted only via the floor truss to the bolt and to the column as a shear force. The shear force is evidently produced by gravity.

Incorrect. The floor truss does not transmit any weight through any bolts to the columns. The bolts are in place only for stability and transmittal of WIND forces from the floor diaphragms to the columns. Perhaps you should have looked at a detail of the construction again:

On the exterior columns the truss bears on an angle seat. In the interior it bears on a stiffened plate on the outside of channel. There is no load-path in which vertical forces are transmitted through bolts.

As no displacements (except elastic ones) take place under normal circumstances, there is no release of any energy. The resistance of the floor is quite good ... for furniture and people on it.

Complete lack of understanding of engineering principles. Notice in the picture above a "damping unit". When the truss flexes, this damping unit removes energy from the system. It's probably about 10% of critical damping. Not that you even know what that term means. Engineers will perform a vibration analysis on every beam system to verify that the beam system is serviceable. To you laymen (and that includes you Heiwa), serviceable just means that the floor system is usable and doesn't vibrate so much that it distracts the occupants. We (engineers) put in vibration damping systems to remove vibrational energy from people walking.

This is a fairly standard practice in all steel buildings and any engineer should know. Heiwa doesn't understand this.


[/quote]BTW - the shear force also produce bending in the floor truss, but the bending moment in the truss at the bolt is zero so no bending is transmitted to the column.
[/quote]
Again, this is wrong. The floor load will produce a bending moment in the column because the point of application of the vertical force is not at the centerline of the column. Almost all simple beam-to-column connections have this.

If the top mass is very big, the bolt may shear off or the floor truss will fail locally due bending. In either case the column will never be damaged by an excessive weight on the floor.

This is somewhat wrong. If the building (under normal operating conditions, i.e. not 9/11) is overloaded on every floor, column failure may occur. This is due to live load reduction. Live load reduction is trick in which engineers can reduce the live load acting on columns based on the certain knowledge that even if one or two floors is under a full live load conditions, the others are certainly far below. In the case of the WTC, the live load reduction is about 50%. In other words, the columns are designed to resist 50% of the live load that the floor trusses are. This comes out to be about 50psf.

In addition, the floor trusses were designed to be serviceable at 50psf, but they have an ultimate capacity of 200psf. Ultimate capacity means that the truss and floor system will be permanently damaged but that the assembly will not fail. In essence, the floors can support 4 times more live load than the column.

This also doesn't have a part in understanding the mechanics of the collapse on 9/11, but it just goes to show that Heiwa can't find his rear end with both hands when it comes to buildings. Statements like, "..the column will never be damaged by an excessive weight on the floor." just go to show he has no clue as to what he's talking about.

 

[Apollo20]

Heiwa:

Thanks for your comments, but I am sorry to see that you are still being totally inflexible in your position! And I wonder why you keep raising the same old objections to particular details of my (and other well-known) collapse calculations as if these details are crucial to the models in question. Or more importantly, if inaccuracies in these models prove anything about the actual collapse of WTC 1 & 2!

As I say Heiwa, I have heard a lot of these objections before: the upper section was not intact and undamaged when it fell on the lower section; the columns got stronger in the lower part of the towers and should have arrested the collapses; there was mass shedding during the collapse so the momentum did not build up; there was insufficient kinetic energy to pulverize the concrete, etc, etc, …. However, I feel confident that none of these objections are what might be called “show-stoppers” when it comes to my collapse calculations or indeed those of other researchers such as Bazant, and Seffen. In fact I have modified my original calculations to include things like crush-up, mass shedding and concrete comminution and guess what happens Heiwa, ………… the buildings still fall down!

And quite frankly I have to say that alternative collapse theories that assume explosives were involved in the collapse of WTC 1 & 2 are quite ludicrous to the point of being pure sci-fi fantasy. I mean come on Heiwa, don’t you think the idea of pre-planted explosives in WTC 1 & 2 is totally impractical? No? So tell us, because inquiring minds need to know, what kind of explosive do you think was used? TNT, TATP, PETN, RDX, HMX, ANFO? And how much do you think was placed in each tower – 5 tonnes, 50 tonnes, 500 tonnes? Well, whatever explosives scenario you choose Heiwa, could you explain how the charges were placed to survive the aircraft impacts and fires. And, please tell us: Is there ANY explosive out there that can survive exposure to a jet fuel fire?

And do you really believe that someone watched the towers that day and decided to push that detonator button 56 minutes after WTC 2 was hit and again, 102 minutes after WTC 1 was hit, or did he/she have the explosives set to go off on a timer like they do in the movies? Count Down to Armageddon indeed!

Please think long and hard about this Heiwa, ……… your reputation depends on it ……… do you really believe this kind of crap?

 

[applecorped]

After 750 posts I doubt he will backtrack now.

 

[Heiwa]

Heiwa:

Thanks for your comments, but I am sorry to see that you are still being totally inflexible in your position! And I wonder why you keep raising the same old objections to particular details of my (and other well-known) collapse calculations as if these details are crucial to the models in question. Or more importantly, if inaccuracies in these models prove anything about the actual collapse of WTC 1 & 2!

As I say Heiwa, I have heard a lot of these objections before: the upper section was not intact and undamaged when it fell on the lower section; the columns got stronger in the lower part of the towers and should have arrested the collapses; there was mass shedding during the collapse so the momentum did not build up; there was insufficient kinetic energy to pulverize the concrete, etc, etc, …. However, I feel confident that none of these objections are what might be called “show-stoppers” when it comes to my collapse calculations or indeed those of other researchers such as Bazant, and Seffen. In fact I have modified my original calculations to include things like crush-up, mass shedding and concrete comminution and guess what happens Heiwa, ………… the buildings still fall down!

And quite frankly I have to say that alternative collapse theories that assume explosives were involved in the collapse of WTC 1 & 2 are quite ludicrous to the point of being pure sci-fi fantasy. I mean come on Heiwa, don’t you think the idea of pre-planted explosives in WTC 1 & 2 is totally impractical? No? So tell us, because inquiring minds need to know, what kind of explosive do you think was used? TNT, TATP, PETN, RDX, HMX, ANFO? And how much do you think was placed in each tower – 5 tonnes, 50 tonnes, 500 tonnes? Well, whatever explosives scenario you choose Heiwa, could you explain how the charges were placed to survive the aircraft impacts and fires. And, please tell us: Is there ANY explosive out there that can survive exposure to a jet fuel fire?

And do you really believe that someone watched the towers that day and decided to push that detonator button 56 minutes after WTC 2 was hit and again, 102 minutes after WTC 1 was hit, or did he/she have the explosives set to go off on a timer like they do in the movies? Count Down to Armageddon indeed!

Please think long and hard about this Heiwa, ……… your reputation depends on it ……… do you really believe this kind of crap?

Apollo20:

The topic is of course collapse arrest and why it is not considered by FEMA, NIST and you. Collapse arrest is when a stable state of a partially damaged structure has developed. It is normally the result of local failures. When one part fails, the force carried by that part is shifted somewhere else, further local failures may occur but in the end, due to the redundancy of the structure, at some stage no more local failures will take place.

You are taking too much for granted in your analysis, e.g. the local failures that initiated the collapse.

The south wall of WTC1? Only evidence of buckling is an enhanced photo showing a large area with a maximum indent at one point of 55 inches. Very strange deformation pattern, actually? How could it have developed. Floors connections failed? I doubt it. The photo does not appear real.

Assuming that no vertical forces can be carried in any columns in the south wall due buckling or lateral deformation, I would assume that these forces are transmitted as shear via the spandrels to the east and west walls. Or that some of the same forces are carried as shear through the hat truss to the core. Thus there is no displacement of the south wall (it hangs on to the adjacent structure) and no release of any energy.

If the south wall initially carried 15% of the total mass above maybe 5% is transmitted to the east wall, 5% to the west wall (via spandrels) and 5 % to the core (via the hat truss) if the south wall cannot carry any load. And as these other parts were originally rather low stressed they should be able to carry the extra load. Redundancy.

That the upper block is demolished prior any structural damage of the lower structure is seen is quite clear from all videos. The mast on top of the roof disappears very early. In your version in the latest ASCE paper the mast should be the last part to be demolished in a push-up after complete collapse. Actually, the whole 58 metres high upper block + mast should be visible during the collapse. But it is not. How can the mast drop due to some local failures 58 metres lower down? Do a correct analysis of that, to start with.

Your one-dimensional model is very crude. One force F, free fall displacement d, etc. Reality is not like that. There are many parts and forces F and you have to keep track of them. If one part fails and F is transmitted you have to establish where it applied then and what happens there, if displacements will occur, etc, etc. I have described it many times.

Regarding what caused the many local failures and displacements seen on the videos of the lower structure adding up to total global collapse, it is evidently up to speculation in view of the sloppy analysis of the early structural failures prior to initiation and no real forensic analysis of the steel parts in the rubble, e.g. in what way the columns were ruptured. But I do not speculate. In my calculations the gravity forces are not sufficent to cause global collapse, only local failures. Unfortunately many readers of my articles object to the conclusion without looking at the assumptions and calculations.

Don't worry about my reputation. It is quite good and I feel fine even if OT.

 

[Heiwa]

I don't typically respond to Heiwa's drivel, but this post is full of such idiotic things that I'm going to take apart his post a bit and show where he doesn't have a freaking clue as to how buildings are designed.



Incorrect. The floor truss does not transmit any weight through any bolts to the columns. The bolts are in place only for stability and transmittal of WIND forces from the floor diaphragms to the columns. Perhaps you should have looked at a detail of the construction again:

You are of course partially right. The vertical (shear) force in the truss is evidently also transmitted to the column via the small angle bar welded to the column on which the truss is resting. The two vertical bolts are there to secure the connection vertically and horizontally and can transmit horizontal (wind) forces as shear (as you point out and which I also mention in my articles)

It doesn't change anything in my analysis. The connection is a simple pin joint. It cannot transmit any real bending transmitted by the truss.

But, if the vertical bolts are not there and you load the floor truss vertically, the floor truss may very well slip off the small angle bar horizontally! This is evidently prevented by the bolts ... and by shear forces in them!

So you see, the bolts are required transmit a vertical load on the truss to the column.

 

[Architect]

You know nothing about buildings, do you?

 

[Architect]

I have difficulty to follow:

What localised failures are you talking about? The outer walls bucklebending inwards at around floor 96? Reason? The floor bolts sheared off at the walls and that the floors dropped down a little - still attached at the core, I assume. Ok, I can follow that.

Firstly, I think you should be aware that "bucklebend" is not a term commonly used in structural engineering. I'm unclear as to whether you'r translating something poorly, trying to simplify terminology "for children", or just don't have a clue. I suspect the last.

Floors sag. Floors pull outer envelope inwards. Other trusses fail, outer sides collapse onto floor, loadings increase further exacerbating deformation of the outer envelope. Really, I thought you claimed to have studied the NIST findings?

But what adjacent panels are you talking about? The wall columns bucklebend locally and that means that the wall above will displace downwards. As the wall above is connected to the core via floors, the wall will try to pull the floors with it. The weakest link is the floor bolt but it will not shear off at this step because the wall is now hanging on the hat truss.

The outer envelope comprises a series of staggered panels which will act to form a natural arch following failure of a localised area, hence my comment. Really, read the NIST report and take a look at the drawings - but don't waste my time with your own ignorance.

Is that what you mean? I cannot see any panels here - and failures transmitted to them.

Yes, well, you claim that there was no great bowing despite evidence to the contrary so forgive my cynicism.

So the wall is hanging on the hat truss and the hat truss transmits the load to the core. Very well.

No, the point is that the load exceeds the capacity of the structure to do so and hence failure of the loadbearing envelope occurs (amongst other things). Try that NIST report.

If the hat truss doesn't fail and the wall drops down (and a piece of the hat truss), the forces involved will be transmitted to the core. No energy has been released so far. Only forces have been shifted around. You agree? This is what happens due local failures. Forces are shifted around.

No, I don't agree. You're talking bollocks.

So now extra forces are carried by the core and the stresses there increase.
You agree?

Erm, wrong.

How much? So that the core columns start to buckle. Why not? Where? Of course where they are weakest = just below the hat truss.

So let's assume the core columns up top deform and the structure attached displace downwards and any potential energy released is consumed by the deformations in the core.

Wrong again.

No free fall. No impact!

Wrong wrong wrong wrong wrong.

Actually it is very frequent when local failures occur for any reason (a columns is heated and buckles!) and forces are shifted about (the force in the column must move somewhere else!) that local failures occur at other locations (where the force is now applied).

Free falls and impacts are very rare. Never occur, actually (apart from loose furniture that slides to the side and out of a window).

You seem to be a bit confused here, not helped by clinging to free fall like a drowning man with a lifebelt.

To state that loads will always be redistributed is clearly wrong. It depends upon the design and capacity of the structure, together with the imposed loads themselves. To generalise as you ahve isn't just wrong, it's incompetent and falls below the standard one would expect of a trained engineer.

Pls clarify what you actually mean. Adjacent panel?

Still not so hot on the old reading comprehension, eh?

 

[Heiwa]

Floors sag. Floors pull outer envelope inwards.

But the bolts must not shear off so that the floor drops down.

 

[Architect]

Stick with the reading comprehension.

 

[Heiwa]

Stick with the reading comprehension.

The scenario of what happens due to local failures in a steel structure is just an example to demonstrate the case for collapse arrest in steel structures as illustrated by
http://heiwaco.tripod.com/WTC1sliceb.GIF

For full explanation you have to read http://heiwaco.tripod.com/nist3.htm . I have changed the title too as I have encountered a lot of blurred thinking on this thread, e.g. about bolted wall connections.

Evidently if you remove a support of a part of a structure, further local failures may happen to other parts attached to this part, in this case 58 metres higher up. You cannot assume that the whole structure above falls down when removing one support, etc, etc.

Hopefully everybody agrees with the new ending of my article:

In the struggle against great organized forces of intolerance and insane self-assertion it is important that scientific reports, papers and analysises of damaged and destroyed steel structures are done using correct thinking, right feeling and proper estimating of facts. Confused thinking, bad passions, erroneous assumptions and haste do not contribute to a better understanding of the world around us.

 

[Architect]

You have had numerous - numerous - errors in your paper pointed out to you on many, many occasions. You have failed to respond meaningfully to these issues, either ignoring technical inconsistencies or deliberately misconstruing the fundamental issues. In short, your paper and your request for review are of no practicable worth.

In fact it is you who are guilty of confused thinking, bad passions, erroneous assumptions, and haste.

 

[Heiwa]

You have had numerous - numerous - errors in your paper pointed out to you on many, many occasions. You have failed to respond meaningfully to these issues, either ignoring technical inconsistencies or deliberately misconstruing the fundamental issues. In short, your paper and your request for review are of no practicable worth.

In fact it is you who are guilty of confused thinking, bad passions, erroneous assumptions, and haste.

Any examples, please? Copy/paste any sentences in my article and point out any confused thinking, bad passions, erroneous assumptions.

 

[ElMondoHummus]

Any examples, please? Copy/paste any sentences in my article and point out any confused thinking, bad passions, erroneous assumptions.

That was already done in other threads.

http://www.internationalskeptics.com/forums/showthread.php?t=102407
http://www.internationalskeptics.com/forums/showthread.php?t=108273
http://www.internationalskeptics.com/forums/showthread.php?t=102629&page=3

 

[Myriad]

Any examples, please? Copy/paste any sentences in my article and point out any confused thinking, bad passions, erroneous assumptions.

Confused thinking etc. in the first paragraph:

The official explanation of the WTC 1 global collapse is that the alleged release of potential energy (PE), of the mass of an upper block above all supporting columns after buckling due to downward, alleged near free fall movement in an initiation zone and impact of a structure below, exceeds the strain energy (SE) that can be absorbed by the same columns below and that all this was due to gravity only

The initial buckling was not due to downawrd movement, it was due to overloading. That is, greater redistributed load forces than the remaining members could support. Downward movement was the result of those forces and of the buckling.

The initial buckling at collapse initiation was not due to an impact, it was due to overloading.

NIST did not allege any near free fall movement at collapse initiation. Free fall movement is not necessary to initiate or sustain collapse and the NIST report did not say that it was.

The mass that moved was not "in an initiation zone," it was the entire mass above the initiation zone.

From NIST report - NISTNCSTAR1-6D chapter 5.2:

"The aircraft impacted the north wall of WTC 1 at 8:46 a.m. … between Floor 93 and Floor 98. … The subsequent fires weakened structural subsystems, including the core columns, floors and exterior walls. The core displaced downward … At 100 min (at 10:28:18), the north, east, and west walls at Floor 98 carried 7 percent, 35 percent and 30 percent more gravity load loads … and the south wall and the core carried about 7 percent and 20 percent less loads, respectively., … At 10.28 a.m., 102 min after the aircraft impact, WTC1 began to collapse. … The release of potential energy (PE) due to downward movement of the building mass above the buckled columns exceeded the strain energy (SE) that could be absorbed by the structure. Global collapse ensued."

I have already shown out in another thread, and in detail, how this is a dishonest quotation. Sentences from different pages of the report have been merged together into one paragraph, the ordering of the sentences has been changed, and phrases and clauses have been removed in a way that changes the apparent meaning of the remaining words.

Confused thinking in your next few lines:

The major problems with this cause are that fires normally only cause local failures, deformations and displacements of steel structures that are soon arrested, and that there are

(1) no evidence that the core displaced downward, as it could not be seen,

False. There is evidence. The outer structure clearly displaced downward. If the core did not also displace downward, then it would have remained visible above the roof line beneath the antenna at its original height. It did not. Therefore it displaced downward.

(2) no evidence of any simultaneously buckled visible columns in the fire zone - no such damaged, buckled, columns have been retrieved from the rubble;

False. The simultaneous buckling of visible columns in the fire zone began before the collapse, and these buckled columns were photographed before the collapse in their buckled condition. This is evidence of buckled columns in the fire zone.

Many damaged buckled columns were retreived from the rubble. You have been shown photographs of many of them.

(3) no signs of drop of the building mass above the buckled columns - the upper block - at near free fall speed a certain height and time as a rigid, solid mass and associated release of potential energy, PE, and

Muddled thinking. The photographs in your paper (and many others) show the building masses above the fire zones dropping. (If they did not drop, then they should still be there.) It is not necessary for them to drop at near free fall speed to release potential energy. It is not necessary for them to fall as a rigid solid mass in order to release potential energy.

(4) no indications of an impact (the PE is now kinetic energy, KE) between the rigid, upper block and the non-rigid structure below at which perfect alignment is necessary.

There are clear indications of an impact between the upper block and the lower block, as the upper block was moving toward the stationary lower block and therefore an impact could not possibly be avoided. There are clear indications that the upper blocks intiially remained rigid because they rotated as a body and were photographed doing so. No one least of all NIST claim that perfect alignment "is necessary." In fact, the observed rotations of the upper masses show conclusively that perfect alignment did not occur.

(Had perfect alignment occurred, the lower structure would have been more resistant to collapse, so "best case" models biased against sustained collapse use perfect alignment as a limiting case to show that collapse would have occurred even then.)

These four conditions are required for the upper block to commence destroying the structure below.

False. Free-fall or near-free-fall collapse is not required. Falling as a rigid solid mass is not required (though it happened anyhow). Perfect alignment is not required. Simultaneous buckling of columns in the fire zone was observed and photographed.

Wow, that's a lot of wrong (confused thinking, false statements, dishonest quoting, and erroneous assumptions) in just your first page. Fix those up, and then we can talk about the rest.

Respectfully,
Myriad

 

[Heiwa]

Confused thinking etc. in the first paragraph:




1.The initial buckling was not due to downawrd movement, it was due to overloading. That is, greater redistributed load forces than the remaining members could support. Downward movement was the result of those forces and of the buckling.

The initial buckling at collapse initiation was not due to an impact, it was due to overloading.

NIST did not allege any near free fall movement at collapse initiation. Free fall movement is not necessary to initiate or sustain collapse and the NIST report did not say that it was.

2.The mass that moved was not "in an initiation zone," it was the entire mass above the initiation zone.




3. I have already shown out in another thread, and in detail, how this is a dishonest quotation. Sentences from different pages of the report have been merged together into one paragraph, the ordering of the sentences has been changed, and phrases and clauses have been removed in a way that changes the apparent meaning of the remaining words.

Confused thinking in your next few lines:




4. False. There is evidence. The outer structure clearly displaced downward. If the core did not also displace downward, then it would have remained visible above the roof line beneath the antenna at its original height. It did not. Therefore it displaced downward.




5. False. The simultaneous buckling of visible columns in the fire zone began before the collapse, and these buckled columns were photographed before the collapse in their buckled condition. This is evidence of buckled columns in the fire zone.

Many damaged buckled columns were retreived from the rubble. You have been shown photographs of many of them.




6. Muddled thinking. The photographs in your paper (and many others) show the building masses above the fire zones dropping. (If they did not drop, then they should still be there.) It is not necessary for them to drop at near free fall speed to release potential energy. It is not necessary for them to fall as a rigid solid mass in order to release potential energy.




7. There are clear indications of an impact between the upper block and the lower block, as the upper block was moving toward the stationary lower block and therefore an impact could not possibly be avoided. There are clear indications that the upper blocks intiially remained rigid because they rotated as a body and were photographed doing so. No one least of all NIST claim that perfect alignment "is necessary." In fact, the observed rotations of the upper masses show conclusively that perfect alignment did not occur.

(Had perfect alignment occurred, the lower structure would have been more resistant to collapse, so "best case" models biased against sustained collapse use perfect alignment as a limiting case to show that collapse would have occurred even then.)




8. False. Free-fall or near-free-fall collapse is not required. Falling as a rigid solid mass is not required (though it happened anyhow). Perfect alignment is not required. Simultaneous buckling of columns in the fire zone was observed and photographed.

Wow, that's a lot of wrong (confused thinking, false statements, dishonest quoting, and erroneous assumptions) in just your first page. Fix those up, and then we can talk about the rest.

Respectfully,
Myriad

1. ?? Of course the dispacement downward is as a result of (after) the alleged buckling. Clear from the text.

2. The mass is not moving into the initiation zone. It would appear the masses above are being split into many parts.

3. It is the last sentence of the quotes that is important.

4. Why differentiate between outer walls and core?

5. Only alleged deformation is alleged to be seen - no buckling.

6. ?? See 2. The upper block, supposed to be intact until end of push-down, is clearly being serioulsy damaged prior any damage to the structure below.

7. No impact (or free fall) is evidently seen! It should have been associated with a jolt + local destruction of the upper block. The upper block cannot remain intact after an impact.

8. ?? If there is no free fall, there is no energy to initiate a global collapse.

Sorry, I think the introduction is quite clear. No errors there and no need for changes.

And Bazant, Greening, Seffen & Co insist on only one solid upper mass/upper block, free fall of same mass/upper block + impact, no destruction of the upper block, etc., none of which is true, in their one-dimensional, very crude, analysis. NIST is worse - only misty release of PE (amount ??) that is proposed to exceed the SE of the structure below without any evidence or calculations on 10 000 pages. That's not the way to analyse an alleged gravity only driven collapse.

As I say, you have to keep track of all the 280+ forces acting on the lower structure in the columns and see what happens when local failures occur in the initiation zone. None of the scientists does it.

If you remove columns in the initiation zone (local failures) and some forces cannot be transmitted to the lower structure, evidently these forces will affect only the upper block and cause local failures there unless the forces are transmitted via the upper block without local failures in the upper block to other columns in the initiation zone and causing more local failures there.

You follow? The trick to mislead the public is that named scientists and authority assume there is only one force acting on the structure below and that its only support is removed and that the only force is then displaced downward by gravity producing one quantity of (enormous) energy (very passionate) that is applied to the lower structure (not missing it).

In fact there are 280+ forces acting on structure below. Remove the connections of say 60 forces to the lower structure (in the south wall) and see what these 60 do to the upper block. They have to find a new way through the upper block down to the structure below. If local failures occurs associated with downward displacement you must of course establish the force and displacement of each to calculate the energy released and then see what happens to that energy. Consumed to produce the local failure, consumed to cause deformations, lost outside the structure, applied to other parts? There are many possibilities ... and in normal cases further failures, deformations and displacements are normally arrested after a while.

This happened when the north wall was damaged 100+ minutes earlier. 35 connections of upper forces were removed and the 35 forces found other ways to the structure below. No displacements. Collapse was arrested at once.

But thanks for your comments anyway.

Kind regards

Heiwa

 

[Newtons Bit]

Myriad: and now you know what Heiwa's specialty is: write B.S. and waste our time.