The Heiwa Challenge

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SteveAustin said:
If 29,000,000 pounds is the carrying capacity of 1 floor (not doubting you)...

Is this why the floor could not support the weight of the collapsing top section? Because the top section weighed more than 29,000,000 pounds?

That is the essential NIST theory boiled down in a nutshell is it not?
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No, there's a good deal more to it than that. For a start, there's the difference between static and dynamic loading. Everything has some elasticity, and hence will deform under load. If a weight is placed on top of an undeformed object, that object will be compressed by the load. However, that compression means that the weight moves downwards, so, at the point where the object has deformed enough to bear the weight, the weight is moving. The object then has to exert a force to stop it moving, and it can be shown that the maximum force exerted is twice that of the static weight. Therefore, the top section not only weighed more than 29,000,000 pounds, but also it exerted at least twice that force on the lower section. "At least", because it wasn't placed gently on the top of the lower block - in which case it would have exerted exactly twice its weight at maximum deflection - but rather it fell on the lower block, which means that even more force was required to decelerate it to a standstill. Therefore, the floors wouldn't have been able to resist the static loading of the upper section, the dynamic loading was twice that, and the actual loading was even higher; estimates of the actual loading indicate that it was enough to collapse not only the floors, but the support columns as well. However, that wasn't necessary for collapse propagation; the columns were only able to stand when braced by the floor trusses, and were too slender to stand unsupported.

Dave
 
Heiwa said:
Aha, an NB structure for The Heiwa Challenge!

"columns aren't even part of the equation"

LOL!

Yes, a structure only with horizontal elements not supported by anything will have little resistance against global collapse!

Can you provide an example of such a structure!
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Now that is a dismal display of reading comprehension.
 
Dave Rogers said:
No, there's a good deal more to it than that. For a start, there's the difference between static and dynamic loading. Everything has some elasticity, and hence will deform under load. If a weight is placed on top of an undeformed object, that object will be compressed by the load. However, that compression means that the weight moves downwards, so, at the point where the object has deformed enough to bear the weight, the weight is moving. The object then has to exert a force to stop it moving, and it can be shown that the maximum force exerted is twice that of the static weight. Therefore, the top section not only weighed more than 29,000,000 pounds, but also it exerted at least twice that force on the lower section. "At least", because it wasn't placed gently on the top of the lower block - in which case it would have exerted exactly twice its weight at maximum deflection - but rather it fell on the lower block, which means that even more force was required to decelerate it to a standstill. Therefore, the floors wouldn't have been able to resist the static loading of the upper section, the dynamic loading was twice that, and the actual loading was even higher; estimates of the actual loading indicate that it was enough to collapse not only the floors, but the support columns as well. However, that wasn't necessary for collapse propagation; the columns were only able to stand when braced by the floor trusses, and were too slender to stand unsupported.

Dave
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Thanks for that clear and precise response Dave. Beachnut are you paying attention? Do you see what a response should look like? Or are you too caught up in the "beachnut mantra"?

OK Dave let me see if I can explain my thinking about this, and yes I do understand exactly what you said.

First of all, I have often heard that the collapse continued because each floor could not support the weight dropped on it. That is that when taking the collapse into consideration it falls only on ONE floor at a time.

How is it that ONE floor ...say floor number 5 can hold a static load many many times it's 29,000,000 pound carrying capacity? (it does have the other 105 floors above it after all) Which of course means that it is not ONE floor alone that carries the static load but a number of floors connect to each other working together as a "block".

I mean anyway you look at it floor number 5 is supporting 105 floors above it and it does not do it alone, since a floors carrying capacity is only 29,000,000 pounds.

So if we take floor number 94 and ask how did a floor with a carrying capacity of only 29,000,000 pounds carry the static load of the 16 floors above it the answer is obvious in that it did not...at least not alone.

So why then when taking the collapse into consideration does everyone seem to say that it is only that top floor you need to account for in the collapse progression as it only hits ONE floor at a time? Obviously ONE floor cannot support all the weight of the building above it alone so it is not that every floor supports the entire weight of every floor above it by itself, and in the same way when the upper portion collapses (and here I'm ignoring the fact that that upper portion turns nearly completely to dust before the bottom portion begins it's collapse) it is not just the carrying capacity of each floor alone ONE AT A TIME that has to be taken into consideration for slowing and stopping the collapse of the upper section.

Of course we all know it's not the floors themselves that hold the building up, the floors simply support whatever is put on that floor, it's the steel perimeter columns and core columns that hold up the building. So when the "collapse" begins why do the core columns not seem to have any effect in even slowing down the collapse? The floors may only have a 29,000,000 pound carrying capacity but the core and perimeter columns at the level of floor 5 have been carrying 105 floors of weight for a very long time
 
Tweeter said:
Could we get back to the topic of this thread?
Have any debunkers even tried to complete the challenge?
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How about a new Heiwa challenge then?

Let's have HIM prove his theory correct.

Let's have Heiwa construct the tower, have it inspected and analyzed to be an accurate model of the towers, and then let's see what happens.

If his tower fails to accurately model the towers (like the lemons, sponges, pizza boxes, etc) then he has to do it over again.

When it finally passes, let's see what happens.

This is my official entry to Randi's challenge: Heiwa will now say that lemons, pizza boxes, and sponges are an accurate model.....

I await my million.
 
SteveAustin said:
How is it that ONE floor ...say floor number 5 can hold a static load many many times it's 29,000,000 pound carrying capacity? (it does have the other 105 floors above it after all) Which of course means that it is not ONE floor alone that carries the static load but a number of floors connect to each other working together as a "block".

I mean anyway you look at it floor number 5 is supporting 105 floors above it and it does not do it alone, since a floors carrying capacity is only 29,000,000 pounds. <snip>
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Those loads aren't being held by the floor. They're being transmitted into the basement, sub-basement, and then into the ground, by the columns.

Each actual floor structure was only designed to carry the live and dead load for that particular floor of building contents; also to provide lateral bracing to the columns.

When the upper part of the building begins to move, it falls on the floor as well as the columns, and it greatly exceeds the capacity of the floor, so the floors break. This removes lateral bracing from the columns and makes it much easier for them to collapse.
 
Minadin said:
Each actual floor structure was only designed to carry the live and dead load for that particular floor of building contents; also to provide lateral bracing to the columns.

When the upper part of the building begins to move, it falls on the floor as well as the columns, and it greatly exceeds the capacity of the floor, so the floors break. This removes lateral bracing from the columns and makes it much easier for them to collapse.
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Good advice for The Heiwa Challenge structure builders/designers! Yes, horizontal structural elements like floors don't do very much! They just transmit their local loads (400 kgs/m² vertically in WTC at any floor level 1 or 109) to the really strong elements, guess what? And they may 'brace' these strong elements too.

In a The Heiwa Challenge structure you can do what you like to make any element fail due to gravity forces applied, just remember that top part C must be similar to bottom part A, when you drop C on A assisted by gravity.

Please note that in WTC 1 floor 1 is as strong as floor 109! They just transmit own weight and stuff on them to the really strong elements anywhere in the structure. If you believe, like NIST, that removing weak floors by gravity will produce global collapse of the strong elements, please have a try. New Challengers to The Heiwa Challenge are always welcome.

Bazant & Co have some ideas that the weak elements of an upper part C have the ability to compress anything below in a part A. C produces rubble of A that becomes a part B - rubble - that is really awful ... on paper. The rubble + gravity destroy A. Hilarious. LOL!
 
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Seymour Butz said:
How about a new Heiwa challenge then?

Let's have HIM prove his theory correct.

Let's have Heiwa construct the tower, have it inspected and analyzed to be an accurate model of the towers, and then let's see what happens.
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Something similar was tried way back.

Heiwa was proposing a project for kids ( :eek: )over on his website. This involved welding substantial steel plates to form a water tank, stuck on steel legs. Below the tank would be a platform on which wood, fabric etc would be set alight with diesel as accelerant. The idea was to show that the contraption would not collapse through heat-weakening of the steel.

Naturally, folks asked him to demonstrate that he'd tried this himself and to provide evidence. As expected he blustered and evaded for weeks until people lost interest in the subject. His MO, basically.

Heiwa is a fraud.
 
SteveAustin said:
OK Dave let me see if I can explain my thinking about this, and yes I do understand exactly what you said.

First of all, I have often heard that the collapse continued because each floor could not support the weight dropped on it. That is that when taking the collapse into consideration it falls only on ONE floor at a time.

How is it that ONE floor ...say floor number 5 can hold a static load many many times it's 29,000,000 pound carrying capacity? (it does have the other 105 floors above it after all) Which of course means that it is not ONE floor alone that carries the static load but a number of floors connect to each other working together as a "block".

I mean anyway you look at it floor number 5 is supporting 105 floors above it and it does not do it alone, since a floors carrying capacity is only 29,000,000 pounds.

So if we take floor number 94 and ask how did a floor with a carrying capacity of only 29,000,000 pounds carry the static load of the 16 floors above it the answer is obvious in that it did not...at least not alone.

So why then when taking the collapse into consideration does everyone seem to say that it is only that top floor you need to account for in the collapse progression as it only hits ONE floor at a time? Obviously ONE floor cannot support all the weight of the building above it alone so it is not that every floor supports the entire weight of every floor above it by itself, and in the same way when the upper portion collapses (and here I'm ignoring the fact that that upper portion turns nearly completely to dust before the bottom portion begins it's collapse) it is not just the carrying capacity of each floor alone ONE AT A TIME that has to be taken into consideration for slowing and stopping the collapse of the upper section.
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Actually, yes, it is. The point is that the load is normally borne by the columns, not by the floors. Once the columns disconnect, they aren't bearing the load any more. Unless the top block falls perfectly vertically and without rotation, the columns can never resume their load bearing role, because the upper part of the column will either glance off the part below it or miss it completely. So we have to look at the only other part of the structure capable of arresting the collapse, which is the floor (i.e. the horizontal trusses and the concrete / steel slab between them).

Looking at videos of the collapse, it appears that the actual mechanism was a good deal more complex than a simple pancake collapse; we model it as that simply because it's more amenable to calculation. Most likely there was an internal collapse wave of the floors ahead of the collapse of the perimeter columns, which then fell away because they were incapable of standing unsupported by the bracing of the floor trusses, and we know that the core columns were the last part to collapse because spires were left standing for several seconds after the floors and perimeters had completely collapsed. However, even if we model the collapse using a set of assumptions that are unrealistically biased in favour of the building surviving, we still find that there is more than enough potential energy released in the course of the collapse to destroy the structure completely. In scientific language this means that the WTC towers were metastable; they contained enough energy to destroy themselves, but needed an initial supply of energy to do so. Therefore, the only real issue for NIST to investigate was not how the collapse continued, but how it began; once a metastable state has been supplied with enough energy to overcome the barrier to decay, it will inevitably do so.

SteveAustin said:
Of course we all know it's not the floors themselves that hold the building up, the floors simply support whatever is put on that floor, it's the steel perimeter columns and core columns that hold up the building. So when the "collapse" begins why do the core columns not seem to have any effect in even slowing down the collapse?
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There's really no substitute here for doing the maths. A36 steel typically reaches its elastic limit at about a quarter of one per cent compression, at which point it starts to buckle inelastically; as I understand it, it then absorbs about 10-15 times the energy in inelastic deformation that it's absorbed in elastic deformation. This can all be calculated as a loss of kinetic energy of the lower block, and the expected slowing of the collapse can be worked out. As a simplified handwaving explanation, though, consider a ten foot steel support breaking when a weight falls on it. It will break after shortening by only a few inches, after which it isn't exerting any upward force. Averaging the force out over the fall of the weight, the average force exerted upwards by the steel support is therefore only a few per cent of the maximum force it can exert; most of the time in the course of the collapse, the steel isn't slowing the weight at all, because it's already broken. The effect in slowing the collapse isn't exactly zero, but in the case of the WTC towers it only appears ot account for a second or so of the collapse time. Conservation of momentum, as each floor is accelerated up to the speed of the falling block and decelerates the falling block as it does so, accounts for significantly more.

SteveAustin said:
The floors may only have a 29,000,000 pound carrying capacity but the core and perimeter columns at the level of floor 5 have been carrying 105 floors of weight for a very long time
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Static weight, yes. Once that weight starts moving, it's a lot harder to stop it than it was to keep it still in the first place.

Dave
 
Dave Rogers said:
So we have to look at the only other part of the structure capable of arresting the collapse, which is the floor (i.e. the horizontal trusses and the concrete / steel slab between them).


Dave
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Maybe the strong, intact columns below are capable to arrest the collapse, too? You know, they carry the thin, weak floors that are supposed to arrest the collapse! Maybe they work together. By joining The Heiwa Challenge with a real structure you'll soon find out!
 
Heiwa said:
Maybe the strong, intact columns below are capable to arrest the collapse, too? You know, they carry the thin, weak floors that are supposed to arrest the collapse! Maybe they work together. By joining The Heiwa Challenge with a real structure you'll soon find out!
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The floors are unable to transfer loads to the columns if the connections fail before the collapse can be arrested even assuming the floors themselves could carry the loads in the first place.
 
GlennB said:
Heiwa was proposing a project for kids ( :eek: )over on his website. This involved welding substantial steel plates to form a water tank, stuck on steel legs. Below the tank would be a platform on which wood, fabric etc would be set alight with diesel as accelerant. The idea was to show that the contraption would not collapse through heat-weakening of the steel.

Naturally, folks asked him to demonstrate that he'd tried this himself and to provide evidence.
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The result was as expected. See http://heiwaco.tripod.com/nist1.htm#6 Has been tested several times.
 
Grizzly Bear said:
The floors are unable to transfer loads to the columns if the connections fail before the collapse can be arrested even assuming the floors themselves could carry the loads in the first place.
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Or it is the other way around. Join The Heiwa Challenge with a suitable structure and you'll find out. I know what happens, but a real test is more convincing for feable souls believing in magic.
 
Heiwa said:
Maybe the strong, intact columns below are capable to arrest the collapse, too?
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No, because they never have a horizontal surface of contact with the columns of the upper block and cannot therefore exert a force on it directly; they can only exert a force transmitted through the floor structure, and this is limited by the strength of the floor structure. And in any case, even if the assumption is made that the support columns themselves are able to resist collapse, calculations show that, after a single storey drop of the upper block, even the undamaged columns are insufficiently strong to do so. This has been a common feature of all such calculations with the exception of two: Gordon Ross's, which inexplicably concludes that collapse is arrested because the kinetic energy of the upper block after collapse of the supports is insufficient to cause a collapse of the supports that it has just collapsed; and yours, which assumes without supporting calculations that half the potential energy of the upper block is not transmitted to the lower structure, and then miscalculates the elastic deformation energy of the lower structure.

Dave
 
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