Failure mode in WTC towers

[DGM]

If you have been following what I have been saying you will realize that I believe the central core columns were taken out at the collapse zone and below and this would have caused a huge plate load in the roof plate and hat truss due to the unsupported core pulling down on it from the center. This would have caused the upper areas to drop, center first.

Wouldn't this load be transfered to the parameter columns through the floor trusses causing all of them to pull in from the initiation zone to the roof? You are talking about a large movement.

 

[Furcifer]

There is no physical evidence of high steel temperatures. Why not?

High enough to allow them to bend under the additional load due to the impact. They don't need to melt really now do they? So how high do you think is necessary? Let's see, has structural steel ever bent in an office fire? If the answer is yes, then we need the heat associated with an average office fire.

 

[Heiwa]

The upper block was most certainly not "solid". I think you mean "ridgid".

It was rigid, stiff, not bent in the beginning and it was solid as it was not gas or liquid but it was mostly air anyway! Or like snow!!! Reminds me!

The only gravity driven collapses known to mankind are snow avalanches (or similar), i.e. an upper block of snow that gets lose on a slope due to the gravity force exceeding the friction between the upper block and ground.

In spite of its low uniform density the solid (!) upper block is pretty rigid (!) during the collapse that starts at an initiation zone in the snow. Then the upper block releases potential energy and pushes a lot of snow in front of it (same density as the upper block) that piles up and compresses in the crush zone (density is increased there but the strain energy is small - snow flakes you know!) until it runs out of potential energy ... and the upper block is compressed. Evidently lose snow is thrown up in the air, when the crush zone advances down the slope.

Such a snow avalanche has nothing in common with the WTC1 collapse, even if the upper block of WTC1 had a uniform density similar to that of compressed snow (180 kgs/m3) that sticks together - snow crystals interacting. But this is what the authorities and university professors want us to believe. Potential energy is always potential energy. But is it?

The big difference is that the upper block of WTC1 is a cage of steel columns and trusses of very high density (7800 kgs/m3) but very little volume, floors of less density while the rest of the upper block was air.

Such a block of steel parts does not behave like a solid and rigid block of snow flakes sliding down a mountain slope, even if the potential energy is same.

Reason is that the potential energy released in the snow avalanche can reasonably be assumed to be as uniformly distributed as the density (snow flakes or crystals only).

In WTC1 most potential energy is in the solid parts and throwing a narrow steel part with its potential energy on another steel part below is not easy. High probability that it misses the other part! Then there are less rigid parts (e.g. floors with their potential energies and concrete crystals) but when they are thrown against more solid, rigid parts (e.g. steel beams), the former will be crushed (concrete dust) ... and the latter will remain.

It can be argued that a snow avalanche will break trees, etc in its way (when enough snow piles up against a tree in the way of the avalanche) but you should then note that the tree is only broken in one piece at that time.

The WTC1 upper block avalanche and its potential energy could therefore never break all the 'trees' (= steel columns) below in small pieces.

Another difference is that the upper block of WTC1 seems to disintegrate (or collapse into itself) before anything happens in the initiation zone and before the crush zone is formed below. So the collapse below floor 94 could not have been caused by potential energy/gravity collapse.

 

[DGM]

Am I wrong here? If the antenna moves down independent of the exterior columns the following must be true. Assuming the initiation zone is where the planes impacted.
A) The hat truss must be compromised

B) The floor trusses must be separated from the core columns from the initiation zone up to the roof.

 

[Tony Szamboti]

Wouldn't this load be transfered to the parameter columns through the floor trusses causing all of them to pull in from the initiation zone to the roof? You are talking about a large movement.

The collapse of the central core at the collapse zone first does both. That is why the center of the roof fell first before the roof line and the perimeter columns bowed inwardly at the collapse zone, quite quickly I should add, as can be seen in the video of the South Tower collapse. The roof has two loads on it which is the plate load on the center and the gravity pull down from the perimeter columns buckling at the 98th floor. However, these forces need to be transmitted to the roof after the other structures fail and that is why it is the last to fall.

 

[Tony Szamboti]

Am I wrong here? If the antenna moves down independent of the exterior columns the following must be true. Assuming the initiation zone is where the planes impacted.
A) The hat truss must be compromised

B) The floor trusses must be separated from the core columns from the initiation zone up to the roof.

There is no need for the floor trusses to be separated from the collapse zone to the roof for what was observed to occur.

The hat truss would just be pulled on by the unsupported central core.

 

[Tony Szamboti]

High enough to allow them to bend under the additional load due to the impact. They don't need to melt really now do they? So how high do you think is necessary? Let's see, has structural steel ever bent in an office fire? If the answer is yes, then we need the heat associated with an average office fire.

I think you needed them to get to 650 degrees C to lose enough strength for a collapse to even be possible. Where is the evidence for that?

We don't just need the heat associated with an average office fire. We need the temperature the steel gets to in an average office fire in a building with a steel frame. The fire temperature is usually somewhat higher than the temperature to which the steel is actually heated.

 

[DGM]

The collapse of the central core at the collapse zone first does both. That is why the center of the roof fell first before the roof line and the perimeter columns bowed inwardly at the collapse zone, quite quickly I should add, as can be seen in the video of the South Tower collapse. The roof has two loads on it which is the plate load on the center and the gravity pull down from the perimeter columns buckling at the 98th floor. However, these forces need to be transmitted to the roof after the other structures fail and that is why it is the last to fall.

Why is there no evidence of this in the parameter columns? You know ripples in the siding, popped windows that sort of thing. The video shows no sign of distortion that would be expected if the core was still connected to the floor trusses.

 

[Gravy]

The collapse of the central core at the collapse zone first does both. That is why the center of the roof fell first before the roof line and the perimeter columns bowed inwardly at the collapse zone, quite quickly I should add, as can be seen in the video of the South Tower collapse. The roof has two loads on it which is the plate load on the center and the gravity pull down from the perimeter columns buckling at the 98th floor. However, these forces need to be transmitted to the roof after the other structures fail and that is why it is the last to fall.

It is wrong to lie, Tony Szamboti.

 

[beachnut]

The collapse of the central core at the collapse zone first does both. That is why the center of the roof fell first before the roof line and the perimeter columns bowed inwardly at the collapse zone, quite quickly I should add, as can be seen in the video of the South Tower collapse. The roof has two loads on it which is the plate load on the center and the gravity pull down from the perimeter columns buckling at the 98th floor. However, these forces need to be transmitted to the roof after the other structures fail and that is why it is the last to fall.

Source? Show work? I only ask this based on the fact your paper includes baseless assumptions. Like this.

In the past year there has been an exponential growth in the number of people questioning the explanations we have been given, by official U.S. government bodies, concerning the collapses of the three WTC buildings in NYC on 9/11/2001.

No source just talk. Is your lack of support for baseless assumptions the same for this statement. How do you come up with these ideas? Source?

The controlled demolition hypothesis appears to be the only realistic and sustainable explanation for the evidence observed in the very rapid complete collapses of the three buildings in NYC on Sept. 11, 2001. As it has not been considered by any of the U.S. government sponsored investigations thus far, it is

essential that a new investigation be initiated to determine who would have had access to these buildings
with the ability to plant charges in them, as well as who detonated these charges.​

​

​

Your conclusion in your paper is also baseless, not backed with facts or evidence. In fact your assumptions are wrong. I can point out more, but you have failed to show how you come up with even this statement now. In fact in your paper your argument includes political rant about Iraq and Afghanistan. Support for all you ideas is only in your own head, and you try to fool people by using political feelings. What was your support for your current hand waving?

 

[DGM]

There is no need for the floor trusses to be separated from the collapse zone to the roof for what was observed to occur.

The hat truss would just be pulled on by the unsupported central core.

But the floor trusses are still connected to the core. Why would the exterior columns not move?

 

[Gravy]

But the floor trusses are still connected to the core. Why would the exterior columns not move?

They do. He is fabricating a "reality" he likes, rather than accepting the one that exists.

 

[Gravy]

Speaking of failure, Tony, you said you would be presenting your information about WTC 7 to a District Attorney last work week. Which DA or assistant DA did you speak to?

 

[DGM]

They do. He is fabricating a "reality" he likes, rather than accepting the one that exists.

I know that. My point is if the core was to move from the initiation zone to the antenna the floor trusses being attached would have to show some effect on the exterior columns or detach some how (along the whole height of the upper block).

 

[Tony Szamboti]

But the floor trusses are still connected to the core. Why would the exterior columns not move?

I guess I don't understand why you think the exterior columns didn't move. They certainly did but their movement was a second effect from the center roof collapse and the buckling of the perimeter columns at the collapse zone. They moved a very short interval after the first two situations occurred which then caused them to move.

Imagine a model with a rod in the center of a wafer thin tube connected to it by springs (the floor trusses) every so often, and with a flexible plate connected to the tops of both the center rod and the outside tube. Then cut that rod so far down from the top and let it fall. I'll bet the outer tube crumples parallel to where the rod was cut and the plate moves down in the center just before the top of the tube starts moving down.

 

[Tony Szamboti]

Speaking of failure, Tony, you said you would be presenting your information about WTC 7 to a District Attorney last work week. Which DA or assistant DA did you speak to?

I will get to it Mark when I have the time to do it.

I work nine hour days during the day. Do you?

Since you are right there in NYC why don't you do me a favor and tell them for me? You have my e-mail address, which you have my permission to give them.

 

[beachnut]

I guess I don't understand why you think the exterior columns didn't move. They certainly did but their movement was a second effect from the center roof collapse and the buckling of the perimeter columns at the collapse zone. They moved a very short interval after the first two situations occurred which then caused them to move.

Imagine a model with a rod in the center of a wafer thin tube connected to it by springs (the floor trusses) every so often, and with a flexible plate connected to the tops of both the center rod and the outside tube. Then cut that rod so far down from the top and let it fall. I'll bet the outer tube crumples parallel to where the rod was cut and the plate moves down in the center just before the top of the tube starts moving down.

But you do not believe there was Bowing before failure? Could this be your problem understanding 9/11, or is it your obvious bias to make up CD stuff.

These frames don’t show slow creep, they show sudden failure of the central core itself. They certainly don’t show the perimeter walls failing first. If the central core failed first it would cause the floor trusses,

not to sag, but to follow them downward. In this situation the other end of the floor trusses would apply a tremendous bending moment to the perimeter wall columns, causing them to bow inwardly and ultimately
to fail. It appears that the NIST photo of WTC1, showing inwardly bowed perimeter columns, is a frozen frame taken from video. In this photo the roof of the building and antenna mast are not shown. It would be interesting to see the full video in slow motion, without cropping of the roofline and antenna mast, to determine if the bowing of the perimeter columns occurs after the antenna mast starts moving downward. ​

From your paper, it seems you do not believe in bowing. Thus making your entire world of CD wrong.

 

[Newtons Bit]

"In the case of a column fixed at both ends against rotation, the concept of an eccentric load acting at the end of the column has no meaning. Any moment applied at the end of the column is resisted directly by the supports and produces no bending of the column itself."

....

That's an example of a column fixed at both ends, there was no such thing in the towers. They were moment FRAMES. You still have no concept of that. But let's elaborate on Timoshenko and Gere, they say that the SUPPORTS take out the moment. This is true. The support is the column above and below. Hmmm.....

You sir, are intentionally ignorant.

 

[DGM]

I guess I don't understand why you think the exterior columns didn't move. They certainly did but their movement was a second effect from the center roof collapse and the buckling of the perimeter columns at the collapse zone. They moved a very short interval after the first two situations occurred which then caused them to move.

Imagine a model with a rod in the center of a wafer thin tube connected to it by springs (the floor trusses) every so often, and with a flexible plate connected to the tops of both the center rod and the outside tube. Then cut that rod so far down from the top and let it fall. I'll bet the outer tube crumples parallel to where the rod was cut and the plate moves down in the center just before the top of the tube starts moving down.

How can the center roof collapse without the exterior columns moving at the same time? They are all interconnected through the floor trusses. Do you not think you would see distortions in the glazing from this?

 

[rwguinn]

....

That's an example of a column fixed at both ends, there was no such thing in the towers. They were moment FRAMES. You still have no concept of that. But let's elaborate on Timoshenko and Gere, they say that the SUPPORTS take out the moment. This is true. The support is the column above and below. Hmmm.....

You sir, are intentionally ignorant.

There is a word in the dictionary for that.
Fortunately, civility prevents us from using it here....