• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Failure mode in WTC towers

no facts, just talk, no proof, fantasy silent explosives, no blast effects

realcddeal said:
Beachnut, I guess in your world things can fall vertically down ventilation ducts or elevator shafts and then go sideways and out of the building faster than freefalling matter on the outside of the collapse zone.
Click to expand...
I am a real engineer, with experience; you on the other hand are a truther engineer, who is unable to think rationally on 9/11 for some unknown reason. But what are you talking about, your fantasy CD world is better than your post?

Sorry, but pressure is faster than falling. When I destroyed a house, the dust from the basement was coming out the basement windows, before the roof made it to the ground. Sorry, I cheated; experience beats stupidity every time. Sorry, your thermite/silent explosives are BUSTED.

Too bad you are full of woo on 9/11 issues. No CD, just failed ideas from want to be engineers.

Sorry you can not have blast without the blast sound. You are busted, you are wrong, your ideas on 9/11 are stupid. I read your politically biased paper with many errors. BUSTED

I have seen hundreds of examples of dust coming out of areas of collapsing mass! Why is 9/11 truth so stupid on simple observations and physics?
 
Last edited:
beachnut said:
I am a real engineer, with experience; you on the other hand are a truther engineer, who is unable to think rationally on 9/11 for some unknown reason.

Sorry, but pressure is faster than falling. When I destroyed a house, the dust from the basement was coming out the basement windows, before the roof made it to the ground. Sorry, I cheated; experience beats stupidity every time. Sorry, your thermite/silent explosives are BUSTED.

Too bad you are full of woo on 9/11 issues. No CD, just failed ideas from want to be engineers.

Sorry you can not have blast without the blast sound. You are busted, you are wrong, your ideas on 9/11 are stupid. I read your politically biased paper with many errors. BUSTED
Click to expand...

I am starting to think you are more like a Goofer engineer. I never see you post any calculations. Just a lot of claims.

However, I'll give you the chance to prove me wrong. If you show how pressures from the collapse zone above could have been transmitted to a point twenty stories below and cause enough pressure in a large open area to blow out a window and still be moving at over 100 feet/second then I'll call you an engineer.
 
Last edited:
GregoryUrich said:
NIST distiguishes between member failure and connection failure. Which are you describing?
Click to expand...

Both, for axial compression failures. We should expect to see very little deformation in those members.

The exterior columns that were pulled in are a bit different and things that were subject to more lateral than torsion would look different. There could be a thousand different cases based on location of splices, whether or not the diaphragm was still intact, whether the impact resulted in primarily axial or lateral forces, etc etc etc.

We can only paint what happened with the collapse with broad strokes. As to specific columns that were recovered, we can only speculate.
 
realcddeal said:
I am starting to think you are more like a Goofer engineer. I never see you post any calculations. Just a lot of claims.

However, I'll give you the chance to prove me wrong. If you show how pressures from the collapse zone above could have been transmitted to a point twenty stories below and cause a focused ejection of debris to move at least 35 feet sideways with enough force to blow out a window and still be moving at over 100 feet/second then I'll call you an engineer.
Click to expand...

I bet he could calculate the effective length factor in a moment frame correctly.
 
Newtons Bit said:
I bet he could calculate the effective length factor in a moment frame correctly.
Click to expand...

Well, maybe he can help you understand the difference between conservative design using pinned connections and whether the columns had any level of being fixed.

You didn't win this argument last time.
 
falling building expels air

realcddeal said:
I am starting to think you are more like a Goofer engineer. I never see you post any calculations. Just a lot of claims.

However, I'll give you the chance to prove me wrong. If you show how pressures from the collapse zone above could have been transmitted to a point twenty stories below and cause a enough pressure in a large open area to blow out a window and still be moving at over 100 feet/second then I'll call you an engineer.
Click to expand...
Everybody, please why do you have to do calculation to tell someone his ideas of CD are stupid? Nobody needs to do a single calculation for your stupid ideas on CD. There are no calculation because you present no calculation to prove your point or pure hearsay, made up fantasy tripe. I use the simple no blast effect and no sounds of explosives. You have to prove there were, and there are not, you are BUSTED.

What calculation do you have? You have half baked politically motivated mindless statements saying CD! Look at your name, realcddeal! Look at your mega error paper! Not a single rational calculation, not a single rational thought.

You fail to understand a falling building expels air, you are not a good engineer, you are a truther engineer who pushes lies of CD!

This is why I say that:
realcddeal, your work is off by more than 17 to 27 times!
realcddeal says, in his paper, with a hearsay source!
it is found that the designed for 707 impact would have contained at least 1.4 times or 40% more kinetic energy than what the 767-200ER aircraft could have provided.
Click to expand...
The chief structural engineer for the WTC says FIRST HAND in his own words (NOT HEARSAY)
Leslie E. Robertson said: on being hit by a commercial jet -
" … in our design (a slow-flying Boeing 707 lost in the fog and seeking a landing field). …. . wounded by the impact of the aircraft and bleeding from the fires, both of the towers of the World Trade Center collapsed." http://www.nae.edu/nae/bridgecom.nsf/weblinks/CGOZ-58NLCB?OpenDocument
Click to expand...
I now CALCULATE the impacts on 9/11 were actually 700% to 1100% more kinetic energy than the design 707 impact. If you need some joules or equal TNT numbers please ask, I have them in short term, and long term memory, excel, and word.
707energy.jpg

This is from Robertson's article, first hand, not hearsay. These are facts, not talk, real research not hearsay from books and news sources.
This makes realcddeal's calculations in error over 17 to 27 times! Horrendous error, terrible research and false information all based on hearsay. Is all your work this poorly constructed?
 
Last edited:
bofors said:
No evidence of CD here. Nope, none at all...

[qimg]http://img444.imageshack.us/img444/9301/wtcsmall1056mw9.jpg[/qimg]
Click to expand...


Yeah, setting off explosives AFTER the building is already collapsing. That makes a lot of sense... :rolleyes:
 
Last edited:
realcddeal said:
It is a three column block from the perimeter. You can see the gap between columns. Even in a controlled demolition there would have been no need to use charges strong enough to blow core columns far out of the buildings. Any CD would have been done with a minimum of charges and just enough to cut or blow the column at its weld plane.
Click to expand...

OK, props to realcddeal for calling a spade a spade. While I certainly don't Jell-O with you on many accounts, I can respect you for holding strong to your beliefs and speaking your mind. Too many in the woo camp are complacent to speak their minds against others if it doesn't further their goals.
 
beachnut said:
Just air due to the building falling. Like when a house falls, air rushes out. I wonder why? Your proof of CD is a failure, false, stupid, and not rational. But other than that why are you without a single fact, is it a special talent you have not finding a single fact or rational idea on 9/11?
Click to expand...
I think this whole problem is not debunked, absolutely not. If it is caused by the collapse of the floors it should be visible at those floors possibly with some Gaussian distribution around it. In the south tower's collapse there is a video in which you see some of these isolated effects more than 30 stories below the front. More interesting is that in one of the videos of the north tower (I believe one from the BBC) you see this effect at one area moving very quickly downwards, almost as fast as the falling debris in air, these are not isolated ones. I've heard people talking about the funneling of floors within the frame ahead of the perimeter columns that are destroyed. This is not true I think for the simple reason that the pancaking's speed is limited by momentum transfer and most of the mass was in the floors. An alternative is the theory that says that air is ahead of the pancaking, that sounds more plausible but that has the problem to explain the isolated parts far away imho, because statistically they are too isolated. I believe there was someone over at LC who estimated where they appeared and looked at the construction drawings, I can't find the post back.
 
einsteen said:
I think this whole problem is not debunked, absolutely not. If it is caused by the collapse of the floors it should be visible at those floors possibly with some Gaussian distribution around it. [...]

An alternative is the theory that says that air is ahead of the pancaking, that sounds more plausible but that has the problem to explain the isolated parts far away imho, because statistically they are too isolated. I believe there was someone over at LC who estimated where they appeared and looked at the construction drawings, I can't find the post back.
Click to expand...

I'm inclined to say that this is the most pathetic, incredible reach I've yet seen from the Truth Movement. Let's see these "Statistics" of yours, or you are seriously talking out of your hat.

Fair warning, I am quite conversant in statistics and experimental technique. Don't try to snow me.
 
Last edited:
einsteen said:
I think this whole problem is not debunked, absolutely not. If it is caused by the collapse of the floors it should be visible at those floors possibly with some Gaussian distribution around it. In the south tower's collapse there is a video in which you see some of these isolated effects more than 30 stories below the front. More interesting is that in one of the videos of the north tower (I believe one from the BBC) you see this effect at one area moving very quickly downwards, almost as fast as the falling debris in air, these are not isolated ones. I've heard people talking about the funneling of floors within the frame ahead of the perimeter columns that are destroyed. This is not true I think for the simple reason that the pancaking's speed is limited by momentum transfer and most of the mass was in the floors. An alternative is the theory that says that air is ahead of the pancaking, that sounds more plausible but that has the problem to explain the isolated parts far away imho, because statistically they are too isolated. I believe there was someone over at LC who estimated where they appeared and looked at the construction drawings, I can't find the post back.
Click to expand...
No, the pan caking speed is not momentum limited. In fact, the simple failure of floors due to weight would proceed and accelerate as you see in the actual failure on 9/11. The floors can only hold 29,000,000 pounds, and then they fall. The core can hold the whole building along with the shell, and both need the floors! This is the unique design of the WTC and its incredible strength. With just a pancake collapse of floors only, the event would be as fast as 12 to 16 seconds, leaving the exterior and core alone. Silly model, but very true. I have to run the numbers but the floor would instantaneously fail with over 29,000,000 pounds, and when the next floor is reached, it fails and adds to the mass, which accelerates at g, and we have a very rapid destruction. Do not fall for the lies of idiots in 9/11 truth. Run a simple model and see how the WTC fails very quickly, just the floors. BTW, as seen on 9/11 parts of core, 50 stories, were still standing for sometime after the floors had left for the ground! So that make your ideas kind of wrong.

The compressed air took a fireman on the stairs and blew him down 5 stories! He was in the core of the collapsing WTC, and he was picked up and moved. An explosion blast would have killed him, a compression of air due to the collapsing front would blow him down! You must study the WTC more to understand the big picture. You can not have preconceived ideas, you must find the answers from a neutral mind, not a CT idiot induce trance of stupid.

You are wrong about the floors, you can see them in a video falling and compressing air outward. The floors are the weak link, the core and shell alone hold all the weight of the WTC! It is the floor that can only hold 29,000,000 pounds. That means any more than the weight and force of 6 floors moving down a floor would fail a single floor; or if you just place 11 more floors (just the floors, does not count parts of core or shell helping) on one floor, just put that weight on a single floor, you have failure! So the floors were failing as fast, or faster than the overall failure front because the floors were overloaded as the mass of not only the upper floors impact them, but parts of the core are coming down too and overloading each floor. I hate to imagine what was going down the elevator shafts and stairwells. What made the fireman fly 5 floors down? Air pressure due to the falling building. Just remember the guys rescued from the fallen WTC core were not blown up, one guy was blown down due to wind gusts from the collapsing building. Proof also there were not explosive charges in the core, or building, these guys would have heard the RDX going off. I hope you understand the sound of real explosives, and blast effects on humans.

The compression of air was accelerating and would show up many floors below, in fact it would show up quickly; very quickly; look up something on your own! Propagation of pressure in a vessel, oops, like when you close the front door of your house and the back door flies open; go do a speed check now! Physics experiment 1,000,054; the slam front door, opens back door. Quick.
Darn, why is it when I drop a box in another box, air rushes out the bottom of the box as soon as the other box falls into it (it ran out the top too, it looked like an explosion with all the flour pouring out all over, up and out the bottom too). And these boxes are not tight! Loose fitting box in another box, and air comes out as soon as the box begins to fall! OH, I was in the subway tunnel, a train many blocks away entered my tunnel and the air was rushing by me well before the train came. Why?
OOPS, I was in a building and felt air moving out of the elevator door while it was closed and the elevator was 35 floors up moving down! Why?
 
Last edited:
A couple of comments, as this is the first time I've looked at this thread.

GregoryUrich said:
Major Tom has, after a review of 100s and 100s of photos, pointed out that columns (both external annd internal) showing member failure (rupture or buckling) represent a very small minority compared to columns failing at their connections (i.e. welds amd bolts). If there was consensus on this issue it would greatly help further the discussion.
Click to expand...

Consensus on this question would have quite an important effect, of course, on collapse time calculations. Since the column splices were at every third floor, then even assuming the plastic deformation energy to splice failure is the same as the energy for a column - which we assume not to be true because of the assumption that all failures occurred at the splices - this means that the assumed failure mode is a plastic hinge at every third floor, giving a three-hinge failure over nine floors rather than one. This reduces the plastic deformation energy by a factor of nine, and even this is an overestimate. If I plug that into Gregory's spreadsheet I get a collapse time of about 13 seconds.

R.Mackey said:
I tend to think this observation biases us towards fracture, shattering and shearing connections without dissipating much energy in the columns themselves -- not quite ala Cherepanov, since at least early in the collapse waves would have been torsional rather than planar, but not completely different from his proposal either.
Click to expand...

It's rather a lot different to Cherepanov, really - he assumed that the initial impact destroyed the entire structure. I'd be a little wary of giving him too much attention.

bofors said:
No evidence of CD here. Nope, none at all.
Click to expand...

And I thought I'd highlight the rare occurence of Bofors actually getting something right.

Dave
 
What interests me is the first 4 seconds of the WTC collapse initiation with the roof dropping and apparently the upper part above the fire/initiation zone telescoping into it, while the outer walls appear straight. Assuming a 60/40 weight distribution walls/core (20 000 tons walls/14 000 tons core above fire zone) and compression <30% yield in the structure, even if all core columns are disconnected/dislocated in one location each (how(?) and cannot transmit any load to the core below) and 100% of the weight above is then carried by the walls, the walls would only compress to <50% yield ... and still hold. They would not crumple up and any outward bendingbuckling would be prevented by the spandrels (like a waist belt).
NIST suggests that all columns 'buckle' in the initiation zone and that the mass above drops down. OK! But if the columns do not rupture but only deform, they would form a nice bumber/fender in the initiation zone and downward movement of mass above would stop at some new equilibrium state.

On the other hand, there seems to be multiple, brittle (?) fractures of the columns, so that parts of columns are ejected horizontally outwards, i.e. an individual column has first ruptured in two locations and the piece in between is ejected. That cannot possibly be caused by mass above and its potential (small) energy and 'buckling'.

Whatever type of initial 'buckling' of a column, it only causes rupture at one location (the weakest or highest stressed point of the buckling mode). I have never seen a structural item (e.g. a column) buckling and rupturing in two points and the intermediate part falling out!
 
einsteen said:
More interesting is that in one of the videos of the north tower (I believe one from the BBC) you see this effect at one area moving very quickly downwards, almost as fast as the falling debris in air, these are not isolated ones.
Click to expand...

I assume you are thinking of this videos:

Normal speed version


Slow motion version


This video is filmed from the north. The collapse of WTC 1 initiated when the south exterior wall in the tower collapsed on floor 98. This caused the upper block of WTC 1 to rotate south while it moved down inside the lower block, where it started to disconnect the floors from the exterior wall on the south side of the lower block, while it at the same time pushed the wall out. Therefore the collapse "wave" had a head start on the south side of WTC 1, before the effect of the collapse spread to the remaining walls. So this what's causing ejections of dust and compressed air at the southwest corner. But the ejections are never ahead of the falling debris on the west side which accelerates away form the dust ejections.

This also evident in the collapse of WTC 2. And if you and Major Tom find the answer to the question beachnut posted at the end of his last post, you will understand the dust ejections lower in the towers and Major Tom will understand the pressure pulses in WTC 1 which was caused by the impact of Flight 175 in WTC 2.
 
Yes! That's the one. I recently downloaded the hi-res one but no time to look at it in detail. It looks like the effect is only at the right side and that's what I mean. So you and beachnut in fact are saying that an assymetrical amount of mass funnels faster than the perimeter columns
are destroyed ? Or is it air ahead of the collapsing mass ? What is it ?
 
Norseman said:
This video is filmed from the north. The collapse of WTC 1 initiated when the south exterior wall in the tower collapsed on floor 98. This caused the upper block of WTC 1 to rotate south while it moved down inside the lower block, where it started to disconnect the floors from the exterior wall on the south side of the lower block, while it at the same time pushed the wall out.
Click to expand...

So the whole south exterior wall collapsed on floor 98? That initiated the whole collapse, subject of thread. Of course not seen on the video linked to, but maybe there are other videos? Showing the south wall!

But the south wall just supported 15% of the total weight of the mass above and was very lowly stressed (20% yield) and little damaged and not heated up very much ... so why would it collapse? And how? Bucklebend out/in or crumple up?

So it rotated south ... I assume you mean the upper part tilted south - but why would it then telescope or slide down inside the 'lower block'? Top is then outside! It would be nice to see a video of the east or west wall, so we can see the top south wall on the outside of structure below. And how the east and west walls 'buckles' from south to north at floor 98, the latter should be seen on the linked video. Where?

And then the upper block started to disconnect floors attached to the south wall below the buckled area at floor 98. OK, it was outside and managed to disconnect floors connected to the inside south wall. Hm! Can you show any videos of that?

If that was the case, the roof and the mast on top 40 metres higher up would have ended up far away to the south and then landed on the ground there.

BTW -what happened to the strong core?
 
Last edited:
You must log in or register to reply here.

Back
Top Bottom