WTC Collapse Simulator - DEMOLITION PROOF.....

[dtugg]

Heiwa, I am waiting to hear about your findings on the news. When is it going to happen?

 

[uruk]

The parts of the upper section may not be destroyed, but will be destroyed and that is the beginning of the collapse arrest.

if the lower floors of the upper section causes damage to the floors below, guess what is going to happen when the rest of the upper section plows through.

The destruction of the upper section will, i.a. cause deceleration.

Only temporarily. As the strcutures below fail they can no longer provide any resistance to the mass of the upper section. And there is still the potential energy due to gravity.

Sure, the mass is still there but it has been slowed down and is in pieces rubbing against each other and friction and further local failures take care of the rest.

That is stupid. If the structures have failed they can no longer provide resistance to the upper section. If they have failed to the point where they are free to move gravity will pull them into the lower floors causing yet more damage.

Friction of the parts of the upper mass rubbing against each other does not subtract from the kentic energy of the mass moving down. That is like saying two choppsticks that are falling towards the floor will slow down if they are rubbing up against each other. Is that what you are impling or have I missinterpreted something?

All energy available is used up So nothing will continue to impact anything. Physically impossible even if Bazant and NIST suggest the opposite. Sorry that the Match Box experiment didn't teach you that. You have completely misunderstood what gravity does. It terrorizes me!

You still don't understand why your matchbox experiment is silly and does not relate to reality. It has everything to do with the structural integrity and arrangement of components of the buildings and the forces involved as the masses are moving into each other.

What frightens me is your apparent lack of simple physics and yet you are employed as a engineer.

 

[Heiwa]

There's some temporary deformation, sure. Absolutely.

But it's temporary, because the matchboxes have the strength and elasticity to recover. Correct?

Now, what would happen if the matchboxes weren't as strong?

At contact there is deformation. Sure. Deformation is there, as long as there is contact. Everywhere.

No, the deformation is not temporary. It varies due to the energy applied during contact and is different in various locations; more deformation close to the contact point, less deformation far away from the contact point.

It means that the deformation can become permanent in certain locations, even resulting in failures, close to the contact point and can be just elastic in other locations, far from the contact point.

Same thing happens when the matchboxes are less strong.

And when the energy applied has produced the relevant deformations and failures, the action stops. Permanent deformations and failures then remain.

Scale does not matter.

You can be sure that the single match box dropping on the 10 boxes will be destroyed before the 10 boxes.

Of course, in this experiment the boxes have same strength, so it is the single box dropping and the uppermost box of the 10 boxes that get destroyed first ... and that's it - if strength is not sufficient. The nine other boxes just deform elastically

In WTC1 the upper part is evidently weaker than anything below that carries it, so it is destroyed first at contact. Quite basic, actually.

To confuse the public, Bazant assumes that the upper part is stronger than anything below - he makes the top part rigid - and then, and only then, global collapse may take place without destroying the upper part first and if there is enough energy available. But there is not enough energy available.

And if there were enough energy available, it would destroy the upper part first.

 

[Heiwa]

Heiwa, I am waiting to hear about your findings on the news. When is it going to happen?

What news? Fox? CNN? ABC, NBC? You must be joking. News?

 

[uruk]

Not at all. You cannot refute reality. In the original Match Box Experiment you drop one Box on a tower of ten Boxes! Very real and easy to do.

By careful observation you notice the deformations of the two objects at contact and observe that the dropped box is deformed X mm and that the 10 boxes are also deformed X mm. The deformation is then reduced as the single Box bounces up. The energy transmitted at contact causing the deformations is transformed into other types of energy. The dropped box motion is arrested.

Don't you understand that the matchboxes are capable of sustaining the forces involved?

It does not apply to the WTC because the building could not structurally withstand the forces involved. The plane impact and fires severly compromised the structural integrity of the buildings.

10 matchboxs can in no possible way come anywhere near to simulate what happend to the WTC. At least not in any sane mind.

In the revised Experiment you drop an assembly of ten Boxes on one Box. Also easy to do.

Now the energy involved is 10 times bigger. By careful observation you notice the deformations of the two objects at contact and observe that the dropped ten boxes are deformed 10X mm and that the single box also deforms 10X mm. The deformation is then reduced as the 10 boxes being dropped bounce up. Energy is transformed from one state to another as explained before.

Again, the match boxs are structuraly capable of sustaining the forces involved. The forces you are using in your matchbox experiments are on many magnatudes less than what the WTC had to sustain in relation to scale. There is no comparison between the matchboxes and the WTC towers. If you cannot see that you are truly hopeless.

Thus, whatever you drop on anything is affected at contact and the bigger object is always less affected than the smaller object. Just keep your eyes open and observe carefully.

That is an oversimplification. You are forgeting about structural integrity, Load capacities, structural design, avenues for progressive collpase, etc.

Just because something is bigger does not mean that the smaller object cannot destroy the larger object or that the bigger object is structuraly stronger that the smaller object. That is being completely infantile
You are ignoring the forces involved, the design and structure of the objects, the structural integrities.

Bazant and Nist close their eyes and assume (conveniently, lazy?) the opposite and suggest that whatever you drop becomes SUPERSTRONG, rigid, and affects (read destroys) anything below it, while it itself is not affected at all by the contact. Global collapse thus ensues ... whenever you drop a object on anything. In any scale!

Wow, now you are just making things up.

Such stupidity really terrorizes me. On whose side are they? OBL's?

I fear for your clients. Especially considering you Pizza box and matchbox experiments.

 

[Minadin]

But it is not gravity that does it - it is the inclined plane. Or more correct, not shown, the force that the inclined plane applies to the object perpendicular to the inclined plane.

Re water flowing downhill, it is only due to the force that downhill applies to the water. If no downhill, the water would drop ... like rain assuming gravity is strong enough!

So, what you're admitting here, is that depending on the direction of the resistance to the force of gravity, there can be a horizontal component to the acceleration vector of a falling object.

Thanks.

I had to snip out a lot or rambling to get to the pith of it.

 

[Heiwa]

That is stupid. If the structures have failed they can no longer provide resistance to the upper section.

Yes, that is stupid! But it is the upper section that should have failed and not the structure below, so the undamaged structure below now provides resistance to the failed structure above.

Please, try to get your parts in order. The upper part is not rigid. It is the first one to be destroyed.

 

[dtugg]

What news? Fox? CNN? ABC, NBC? You must be joking. News?

It doesn't matter to me. Whichever you choose to send your earth shattering evidence to. One in Europe, or Al Jazeera perhaps if you think the American media is crap.

 

[240-185]

According Bazant friction does not exist in global collapses!

No, he didn't say that. He says that air friction is negligible when a debris comes down, because a WTC debris is mooooooooooooooore heavier than a paper sheet.

Minadin's schema is somewhat incomplete; here's a better one:

The three forces that are needed are represented. This is called "principle of inertia". It's a base of Newton's physics. And you aren't able to understand basic physics that students learn in high school. How shameful.

 

[Heiwa]

So, what you're admitting here, is that depending on the direction of the resistance to the force of gravity, there can be a horizontal component to the acceleration vector of a falling object.

Thanks.

I had to snip out a lot or rambling to get to the pith of it.

No, I am not saying anything like that. What are you talking about?

"Depending on the direction of the resistance to the force of gravity". What is that?

"There can be a horizontal component to the acceleration vector of a falling object". What are you talking about???

I do not write like that. Bazant may!

What resistance to the force of gravity? An inclined plane? Friction? Deformation? The force of gravity on a mass m is constant as far as I am concerned, as long as g is constant.

Horizontal component to the acceleration vector of a falling object?

You mean g? It's acceleration is vertical and there is no horizontal component (in a standard frame of reference).

Try to be more clear, please!

 

[Heiwa]

No, he didn't say that. He says that air friction is negligible when a debris comes down, because a WTC debris is mooooooooooooooore heavier than a paper sheet.

Air friction? Yes it is negligible. But we talk about friction between parts like columns, beams, floors rubbing against each other and that is considerable. And Bazant ignores it.

 

[Heiwa]

Minadin's schema is somewhat incomplete; here's a better one:

[qimg]http://pagesperso-orange.fr/laurent.buchard/CroquisLaurent/croquis4.gif[/qimg]

The three forces that are needed are represented. This is called "principle of inertia". It's a base of Newton's physics. And you aren't able to understand basic physics that students learn in high school. How shameful.

Not too bad. But P + R = F can also be 0, i.e. the object does not move at any angle alfa. Solve it for alfa = 90°! Explain why object does not drop straight down!

 

[Grizzly Bear]

Air friction? Yes it is negligible. But we talk about friction between parts like columns, beams, floors rubbing against each other and that is considerable. And Bazant ignores it.

Reading this sentence does remind me of one thing... you criticize Bazant for simplifying his figures in assuming the upper section is rigid during crush down, but it seem you treat the entirety of the lower section as if it's utterly invincible. The only difference is where Bazant does this to simplify the math you're assumming this as a real life scenario.

Friction is only one element, if the constituent parts are unable to sustain such a load then friction or no friction, the structural components will fail. It not only a matter of whether the columns can sustain these loads but whether or not the connections can do the same. The collapse mechanism you keep asserting should have happened with the trade centers sounds more like a mechanism that would be more realistic in a more traditional steel frame structure, not that of the trade centers.

You've oversimplified it beyond any reasonable measure...

 

[PixyMisa]

At contact there is deformation. Sure. Deformation is there, as long as there is contact. Everywhere.

No, wrong.

Deformation can only be everywhere if forces are transmitted without loss throughout the structure, an for that to happen the structure would have to be perfectly rigid, and if it's perfectly rigid it can't deform in the first place.

No, the deformation is not temporary.

Wrong.

The matchbox compresses, just a little, and then rebounds. The deformations is temporary.

It varies due to the energy applied during contact and is different in various locations; more deformation close to the contact point, less deformation far away from the contact point.

Or none at all.

It means that the deformation can become permanent in certain locations, even resulting in failures, close to the contact point and can be just elastic in other locations, far from the contact point.

Or it can be elastic throughout the structure.

Or it can cause permanent failure throughout the structure.

Same thing happens when the matchboxes are less strong.

Yes indeed.

And when the energy applied has produced the relevant deformations and failures, the action stops.

You still have the force of gravity bearing down. Gravity never switches off.

Permanent deformations and failures then remain.

That is what permanent means, yes.

Scale does not matter.

Build a matchbox 1000 times as large in all dimensions, and it will instantly collapse under its own weight.

Scale always matters.

You can be sure that the single match box dropping on the 10 boxes will be destroyed before the 10 boxes.

No, you can't be sure of that. Not only that, but a destroyed matchbox has the same weight as an undestroyed matchbox, and can be used to destroy other matchboxes.

Of course, in this experiment the boxes have same strength, so it is the single box dropping and the uppermost box of the 10 boxes that get destroyed first ... and that's it - if strength is not sufficient. The nine other boxes just deform elastically

What if they're not strong enough?

They deform, you say. If they deform, that means that the dynamic load is greater than the static load. So if they were strong enough to sustain the static load, but not strong enough to sustain the increased dynamic load, they will collapse.

By your own logic, they will collapse.

In WTC1 the upper part is evidently weaker than anything below that carries it, so it is destroyed first at contact. Quite basic, actually.

Quite absurd, actually.

You have all sorts of materials and failure modes going on, and even if the upper part is "destroyed", it weighs just as much as it did before and is applying just as much force as it did before.

To confuse the public, Bazant assumes that the upper part is stronger than anything below - he makes the top part rigid - and then, and only then, global collapse may take place without destroying the upper part first and if there is enough energy available. But there is not enough energy available.

You keep claiming that there is not enough energy available. NIST shows that you are wrong.

And if there were enough energy available, it would destroy the upper part first.

No, and in any case, irrelevant.

 

[Biscuit]

I am guessing that you didn't actually try and drop ten boxes on one and despite the fact that others have explained the point I was making you seem to completely ignore the fact that matchboxes and buildings have absolutely NOTHING in common.

Do you think that structural engineers use matchboxes to test the strengths of their designs? Do they use Popsicle stick bridges to test for weight limits? Do auto companies crash matchbox cars to test for safety? Does boeing put paper airplanes into wind tunnels?

Does concrete and steel perform in the same manner as paper and wood? Why aren't buildings made of the same material as matchboxes?

 

[PixyMisa]

You've oversimplified it beyond any reasonable measure...

Yep. He's taken a statement that is true for certain structures under certain conditions, and asserted that it is true for all structures under all conditions, in defiance of mathematics, physics, engineering, and reality in general.

 

[240-185]

Not too bad. But P + R = F can also be 0, i.e. the object does not move at any angle alfa. Solve it for alfa = 90°! Explain why object does not drop straight down!

Alpha = 90°, the slope does not apply any force R to the object, P equals practically F (plus some negligible air friction).
Go back to school.

 

[Heiwa]

Alpha = 90°, the slope does not apply any force R to the object, P equals practically F (plus some negligible air friction).
Go back to school.

Good that you realize that the slope or inclined plane does not apply any force R. That was my point. Gravity P thus has nothing to do with R! R is just a function of the force applied by the inclined slope on the object (which is what?)

But imagine now that the object still does not drop in spite of alfa = 90°. It is possible if the object is glued to the inclined plane = very big friction. Then P = F someway is transmitted to the inclined (vertical) plane, don't you agree.

Do same with alfa = 180° (object glued to ceiling)! Why doesn't the object drop due to gravity?

 

[Heiwa]

You have all sorts of materials and failure modes going on, and even if the upper part is "destroyed", it weighs just as much as it did before and is applying just as much force as it did before.

Even if? Of course the upper part is destroyed and the interface upper part/lower structure changes and the load it applies to the lower structure is redistributed, local pressures at contact points are reduced and further destruction is arrested.

You always reason as if the upper part remains unchanged after contact. It doesn't. You are reasoning exactly as Bazant! In the real world the upper part could not have remained unchanged, and when it starts to change after contact you have to look again what happens.

That's why the videos, topic of this thread, are wrong showing the upper part intact all the time.

But the videos are still quite good. If the upper part for any reason would have remanied intact, the destruction that follows would have taken much longer time than seen in reality.

So the destruction seen including horizontal ejections of big chunks of wall sections cannot be due to energy provided by gravity.

 

[240-185]

But imagine now that the object still does not drop in spite of alfa = 90°. It is possible if the object is glued to the inclined plane = very big friction.

No. Although there will be a non-negligible air friction, gravity applies a bigger force. A glued object interacts each other with the wall he's stuck to.

Do same with alfa = 180° (object glued to ceiling)! Why doesn't the object drop due to gravity?

Because the glue interacts with the ceiling and the object...