Simulation shows why World Trade Center towers fell: it's the heat

Originally posted by Valhall

Here is WTC 2 at 20 degrees list. (NIST put the highest degree of list closer to 25 so this is conservative.)

These drawings are far from reality, nor does it accurately represent what is in the NIST report.

The report states that the list was 7-8 degrees in one direction, and 4-5 in the other. The 25 degree tilt didn't occur until much later, AFTER the top had fallen far enough to disappear behind the dust.

Also, there ZERO possibility that the "off" side could be under tension. For this to happen, the core would have to be acting as an immoveable fulcrum, or at the very least, requires it to provide a massive amount of resistance to the falling top, AFTER it's buckled and gone out of alignment by 7-8 and 4-5 degrees. Impossible.

Well....If its 2009 that would mean that you've been working for the C.I.A. for how long now?

Originally posted by space cadet
6000 gallons of fuel ignited upon impact per plane. The other 4000 gallons ignited as the buildings collapsed causing the disinegration of everything in it's way. The hijackers made sure the planes were stocked full of gas, it was a priority of which planes were chosen.

Star and flag John, for bringing up the reality of 9/11.

[edit on 18-9-2009 by space cadet]

here is a foundry worker within 5 feet of molten steel, holding bare-handed a rod that is in the molten steel.

www.youtube.com...

but somehow part of the WTC steel girders that were 20, 50, 100 feet from the kerosene fuel flames above, were so weakened, the they practically free-fell into a heap. c'mon, this just defies logic and science.

ignition temperture of jet fuel--approx 410 degrees far.
melting temperture of steel---approx 2750 degrees far.

[edit on 25-9-2009 by jimmyx]

reply to post by jimmyx


I'm sorry....your postnotwithstanding......

It is MISSING the point!!!!

The discussion is is not about....melted steel. Please focus.

Different metals will "melt" at different temperatures.

I could, for instance...bring up the crash of a certain Cessna 150, in the 1970s...at Hawthorne Airport (KHHR)

N8282F

My family OWNED that particular airplane.....a Cessna 150...

BUT ...someone who rented it, CRASHED while landing......started a fire, because the carbureator, which on airplane piston engines is mounted on the BOTTOM>>>>of the engine....

...in the crash, ON THE RUNWAY>>>>a fire started.

Guess what?

The lone "pilot", after the crash, escaped BEFORE the fire engulfed the airpane....(so, he survived...)

Since I had a lot of time in N8282F.... I kept a piece of the melted aluminum chunk, from the wreckage....

Just to clarify, the original airplane....N8282F was a 1966 era Cessna 150. It had only recently, and lovingly, been re-painted to look similar to a Cessna paint scheme for new deliveries...in the late 1970's era....bright green, and avocado green...anyway....it was a favorite airplane, DESTROYED by an idiot pilot that we accepted,and alowed to rent...and still, HE managed to crash!!!


He failed, it was determined, during a landing....... PIO......

POINT IS....high heat will MELT aluminum.....I have a chunk of N8282F to attest to that fact.

ALSO....OTHER metals...(not steel, obviously) may melt....so the observaton of "molten metals" at the site of the WTC collapse DOES NOT mean that the "molten metal" seen was steel....but, the term is constantly in use, just to ridicule actual intelligent assessments......

[edit on 25 September 2009 by weedwhacker]

[edit on 25 September 2009 by weedwhacker]

Originally posted by Joey Canoli

The report states that the list was 7-8 degrees in one direction, and 4-5 in the other. The 25 degree tilt didn't occur until much later, AFTER the top had fallen far enough to disappear behind the dust.

Good point. I'm going to redo my drawings with the 7 degrees. While this will decrease the moment arm and the distance of compression on the east side, it does not eliminate the fact that the west side will be in tension. ZERO possibility of it being anything but tension (i.e. - let's make sure we understand what Valhall means by this...there is a tensile stress do to the torquing over of the top of the building. Dependent on the magnitude of that tensile stress the building can be net zero stress on the west wall, decreased compressive stress on the west wall, or true tensile stress on the west wall. I would assume (though I have not ran the calculations) that the net would be decreased compressive stress. So when I say "the building is in tension" I don't necessarily mean net tensile. My apologies for that sloppy way of stating that.)

Thanks for the correction and I'll get back with you.

Also, please note that my question is concerning the core columns in both towers. So while I'm working to get updated drawings for WTC 2 as far as the list is concerned, that question still remains on the table for both WTC 1 and 2.

Originally posted by Joey Canoli
Even if 80% goes outside the footprint, the other 20% remains inside the footprint, and the weight increases as it descends.

I'm not even going to argue with this because it speaks for itself. If anyone with a better understanding of physics wants to talk about this, I'm all up for it. ONE pre-requisite of a smaller mass is a negative acceleration. That's just the FIRST obvious requirement. This person seems to be convinced we are dealing with the incredible hulk, completely unstoppable.

I should also add the total weight of the "pile driver" is NOT necessarily increasing when >80% of the mass is being sent out over each floor. Again, just look at the footprints. The majority of both buildings was sent flying in all directions. That is not only a massive energy sink to move all of that mass laterally, but that is ALL mass that was moved OUT of the system and was unavailable in the end. By the time the collapse reached, say, the 40th floor, most of the mass above is now gone. No longer under the same loading conditions, either, obviously, and the mesh is much stronger lower down because of the greater proportion of weight it was built to carry. And it was happening the entire time the collapses were happening; literally this WAS the "collapse." It's obvious that it should have at least slowed down losing so much mass, if not arrested completely, and even Bazant's paper shows this. That's why he was unable to include the loss of mass in his energy calculation, because it greatly slowed the collapse times and proved his model doesn't fit reality. The reality is that the collapse rate was totally independent of the amount of falling mass.

[edit on 25-9-2009 by bsbray11]

Originally posted by Joey Canoli
... and the weight increases as it descends.

I have to pile on, here...."Joey"

Sorry, but....you didn't mean to write that, the way it came out, did you?

Originally posted by weedwhacker

Originally posted by Joey Canoli
... and the weight increases as it descends.

I have to pile on, here...."Joey"

Sorry, but....you didn't mean to write that, the way it came out, did you?

It depends on how one reads his 80% statement. If he meant something else, I'd be willing to amend my statement.

I read it like this, and I'll include some numbers to make it easier to follow.

1- a floor weighs 10k tons
2- during the collapse, in the distance that the front moves one floor's height, 80% (from bsbray) of a floor's weight is lost outside the footprint.
3- so for each floor'sheight that it falls, 8k tons is lost, but 10k tons is added, for a net gain of 2k tons/ floor's height of fall.

Note that at the end of the collapse, 80% is outside the footprint.

Originally posted by Valhall

Good point. I'm going to redo my drawings with the 7 degrees. While this will decrease the moment arm and the distance of compression on the east side, it does not eliminate the fact that the west side will be in tension. ZERO possibility of it being anything but tension (i.e. - let's make sure we understand what Valhall means by this...there is a tensile stress do to the torquing over of the top of the building. Dependent on the magnitude of that tensile stress the building can be net zero stress on the west wall, decreased compressive stress on the west wall, or true tensile stress on the west wall. I would assume (though I have not ran the calculations) that the net would be decreased compressive stress. So when I say "the building is in tension" I don't necessarily mean net tensile. My apologies for that sloppy way of stating that.)

No, it's quite impossible for it to have any weight at all taken off of it. Can't happen without the fulcrum, as I stated.

Think of it this way: if the core was holding ~50% of the weight in an intact building, after they buckle enough to conform to the 7-8 and 4-5 degree list, what will be their strength? For a vertical column, that much misalignment will result in a SEVERE loss of strength, even if we disregard the fact that the core wasn't in a single plane parallel to the collapse direction. And when we consider that the core was a rectangle - IIRC, about 100' x 80'? - as the building tilts, even just 7-8 and 4-5 degrees, and also taking into consideration that the west wall didn't imeadiately buckle, then it becomes apparent that one side of the core will have descended, say 4', while the other side has descended 6' or so. This means that the core column ends, at the fracture zone, have passed by each other, and CANNOT be giving any resistance to serve as that fulcrum.

In order for there to be ANY tension, or even lessening of the weight on the west wall, your thoughts require that the core, at this point, to be able to hold 100% of its design strength.

I'm sorry if I'm not explaining my thoughts properly to you, but it's just impossible to take any weight off the west wall.

Originally posted by Joey Canoli
1- a floor weighs 10k tons
2- during the collapse, in the distance that the front moves one floor's height, 80% (from bsbray) of a floor's weight is lost outside the footprint.
3- so for each floor'sheight that it falls, 8k tons is lost, but 10k tons is added, for a net gain of 2k tons/ floor's height of fall.

You're not a mathematician, are you? Or a physicist. The mathematical representation you just created has less to do with the actual collapses than pancake theory.

Are you assuming a total free-fall that starts over every 12.5 feet?

Where do you consider instantaneous momentum? Where is the velocity of a "floor" after impact with the "floor" below it, and the changes in acceleration/velocity over time?

Are the "floors" the trusses falling, or are they the columns, or are they both failing instantaneously?

I could go on all day.

Why don't you just draw me a picture of dominoes? It would be about as relevant.

Originally posted by Joey Canoli

Originally posted by Valhall

Good point. I'm going to redo my drawings with the 7 degrees. While this will decrease the moment arm and the distance of compression on the east side, it does not eliminate the fact that the west side will be in tension. ZERO possibility of it being anything but tension (i.e. - let's make sure we understand what Valhall means by this...there is a tensile stress do to the torquing over of the top of the building. Dependent on the magnitude of that tensile stress the building can be net zero stress on the west wall, decreased compressive stress on the west wall, or true tensile stress on the west wall. I would assume (though I have not ran the calculations) that the net would be decreased compressive stress. So when I say "the building is in tension" I don't necessarily mean net tensile. My apologies for that sloppy way of stating that.)

No, it's quite impossible for it to have any weight at all taken off of it. Can't happen without the fulcrum, as I stated.

A beam in bending is in compression on the shortened side and tensile on the lengthened side. I have no idea what you're talking about. The compression load would be decreased.

Okay, the corrections to the previous drawings when applying a 7 degree list are as follows:

Compression on east wall - 12 ft CORRECTION: 12 ft of top portion into 12 ft of bottom portion so 2 floors in compession.
Moment arm from cg of bottom portion of building to cg of top portion of building = 24 ft.

[edit on 9-25-2009 by Valhall]

Originally posted by Valhall


A beam in bending is in compression on the shortened side and tensile on the lengthened side. I have no idea what you're talking about. The compression load would be decreased.

1- the towers weren't a beam.
2- your thoughts assume that there was no buckling of the "beam", and that it still is serving as a fulcrum.
3- your thoughts rely on the momentum to be in the 9 o'clock direction - if going by your previous diagram
4- it wasn't. Due to the buckling of your "beam" at the same time as it was tilting, momentum was in the 6:30-7 o'o'clock direction.

Other than that, you are correct.

reply to post by bsbray11


None of your points address what I wrote.

Try again to show that if for every floor that the collapse progresses, and 80% of a floor's weight is lost during that time, why the falling weight wouldn't increase.

Or address that if it requires 50k tons to collapse a floor, and that requirement is met, why even if there was a 1:1 ratio of weight lost to weight gained from that point on, and the floor connections are the same, why the collapse front wouldn't show zero accel/decel.

Originally posted by Joey Canoli

Originally posted by Valhall


A beam in bending is in compression on the shortened side and tensile on the lengthened side. I have no idea what you're talking about. The compression load would be decreased.

1- the towers weren't a beam.
2- your thoughts assume that there was no buckling of the "beam", and that it still is serving as a fulcrum.
3- your thoughts rely on the momentum to be in the 9 o'clock direction - if going by your previous diagram
4- it wasn't. Due to the buckling of your "beam" at the same time as it was tilting, momentum was in the 6:30-7 o'o'clock direction.

Other than that, you are correct.

The tower structure can be analyzed as a beam on a macro level. The fulcrum point is at the west wall but the moment arm of torque about the cg of the bottom portion of the building is the distance from that cg point to the cg of the top portion of the building. Other than that you're basically wrong...and then 100% wrong at that. I can't help you understand couples, so you'll just have to get a tutor on that one.

By the way, I mis-stated something in the last post. The compression is 12 ft of the top portion into 12 ft of the lower portion - so it's 2 floors in compression.

Originally posted by Joey Canoli
reply to post by bsbray11

 

None of your points address what I wrote.

You're wrong. By ignoring all of those things, you aren't creating a realistic model of the collapses. The second you actually pull out the physical formulas, you're screwed, because you will arrive at the exact same conclusions Bazant did. In case you aren't aware, all of those mass/displacement/time things are integrally related in the formulas. You can't just make up each number, they have to all fit together. So to reiterate, the little mathematical model you just offered to demonstrate a point diverges grotesquely from real scientific laws. And I asked questions that showed its flaws along those lines.

Try again to show that if for every floor that the collapse progresses, and 80% of a floor's weight is lost during that time, why the falling weight wouldn't increase.

The bottom-most floors (everywhere the "collapse wave" has yet to reach) are experiencing less and less loading upon them as so much mass from each floor is blown outwards.

That's just ONE thing that you are failing to consider, along with all of the other things I asked in my last post. I can come up with an asinine mathematical model that you can't debunk, too, but it's still an asinine model. I take it you're a fan of Greening's work, too?

I saw a video a while ago, cant see it now (damn work restrictions ) which showed the collapse of the tower with the antenna on top (can't remember which one). It was slowed down and showed the antenna had started to drop about six frames before the rest of the building began to collapse.
Now correct me if I'm wrong, but does this mean that the core was compromised before the rest of the building?

This could possibly explain the lack of downward deformities found on the core column seats, compared to the exterior columns. But if this is the case, would that not mean that the entire collapse initiation is invalid?

Just curious.

National Geographic? You've got to be kidding...does ANYONE still believe the crap that they put out? Or, for that matter, anything that Popular Mechanics publishes? I understand, though. NG, PM, etc don't require much thinking or evaluating. They just feed you crap and hope you fall for it.

Originally posted by Curious and Concerned

This could possibly explain the lack of downward deformities found on the core column seats, compared to the exterior columns. But if this is the case, would that not mean that the entire collapse initiation is invalid?

Just curious.

Yes, if that were the case, it would.

Why would anyone still be posting in this thread? I mean 20 pages? CMON! NatGeo is bs, FAT BS, and we who are aware of the truth know this... so why a thread like this still getting attention.. did a dis-info agent stir up a good distraction here or what?