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How Does Aluminum Cut Steel?

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posted on Dec, 16 2007 @ 04:00 PM
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Originally posted by Zaphod58
reply to post by OrionStars
 


Do you even understand what that says? It says that the INTERIOR core was concrete reinforced, surrounded by a STEEL STRUCTURE. It does NOT say that the perimeter walls were steel reinforced with concrete.


I understand it quite well. However, you are not indicating you do. The author is telling people what existed inside the tube in tube exterior wall frames. The internal part no one could see unless the exterior steel on the those tube designs exposed the inside of those frames.

How much load bearing support do you think hollow steel is going to have, particularly in buildings the size of the twin towers? I find it incredible that people think hollow steel has any significant load bearing capacity. The author states steel flexes and loses shape. Hollow steel flexes far more easily and loses shape far more easily. And that means no significant load bearing capability, doesn't it?




posted on Dec, 16 2007 @ 04:04 PM
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Well, we've seen the arrival of "9/11 madness" warnings recently.

Is it possible to have a "9/11 deliberately obtuse" warning as well?

Only its obvious to me that certain people have no interest in educating theselves over this, despite overwhelming evidence in links that have been put forward, and explanations given.

Which is kind of sad, because it takes an excellent debating forum and turns it into a schoolyard farce.

To be honest, it puts me off posting altogether.




posted on Dec, 16 2007 @ 04:08 PM
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Tell a lumber supplier you are building an addition to your home. Tell them you want to try a new design. You need 2" x 4" rough framing lumber with hollow cores 1" x 3". Then further explain it is for use as primary load bearers. See what what is stated to you by whoever takes your order.



posted on Dec, 16 2007 @ 04:12 PM
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reply to post by OrionStars
 


Are you building a strawman? Are you saying that there was wood in the exterior of the WTC towers




[edit on 12/16/07 by FredT]



posted on Dec, 16 2007 @ 04:13 PM
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Originally posted by OrionStars
Tell a lumber supplier you are building an addition to your home. Tell them you want to try a new design. You need 2" x 4" rough framing lumber with hollow cores 1" x 3". Then further explain it is for use as primary load bearers. See what what is stated to you by whoever takes your order.


Wood and steel do not have the same dimensional bearing capacity so it's not really a fair question. Just my humble opinion.



posted on Dec, 16 2007 @ 04:21 PM
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Originally posted by FredT

Its all about Mass and velocity


I beg to differ. It is about mass, weight, velocity, momentum, and resistance.



posted on Dec, 16 2007 @ 04:30 PM
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Originally posted by Disclosed

Originally posted by ULTIMA1
Just like an aluminum airframe is not going to cause major damage to the steel beams of the WTC or to penatrate the walls and collumns of the Pentagon.


I'm confused, ULTIMA1. You just said the airframe did not cause major damage....but earlier on 12/8/2007 you stated this?

www.abovetopsecret.com...


Originally posted by ULTIMA1

Originally posted by Zaphod58
Right there he asks if the planes could have hit with more force than you are saying, and you say "no". How is that misunderstanding you????


Well please show me where i stated there was little force.

I stated the aluminum wings and airframe would do that much damage to the steel beams. I never stated anything about there being little force.
[edit on 8-12-2007 by ULTIMA1]


How can the airframe cause that much damage one day, and not cause that much damage a week later?


"That much damage......" has to be read in the context of whatever someone described as damage. Then the word "that" has relevance. Taken out of context, as it was in this case, the word "that" doesn't. "That much damage.....", taken out of context, could mean anything any observer chooses it to correctly or incorrectly mean. The out-of-context "that" could refer to damage anywhere from mild (not all that compromising or not compromising at all) to severe. Exactly what degree of damage was someone referring to, when the response was "That much damage......."?



posted on Dec, 16 2007 @ 04:48 PM
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[edit on 16-12-2007 by SlightlyAbovePar]



posted on Dec, 16 2007 @ 04:59 PM
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Originally posted by ANOK

Originally posted by OrionStars
The following says there was.

911review.org...

“The design was a "tube in a tube" construction where the steel reinforced, cast concrete interior tube, was surrounded with a structural steel framework configured as another tube with the load bearing capacity bias towards the perimeter wall with the core acting to reduce deformation of the steel structure maximizing its load bearing capacity. All steel structures with the proportions of the WTC towers have inherent problems with flex and torsion. Distribution of gravity loads was; perimeter walls 50%, interior core columns 30% core 20%



^This is so wrong...


What I cited refers to the perimeter/exterior primary load bearing framework. Below, you jump over to center core area. Why?


Also unique to the engineering design were its core and elevator system. The twin towers were the first supertall buildings designed without any masonry. Worried that the intense air pressure created by the buildingsâ high speed elevators might buckle conventional shafts, engineers designed a solution using a drywall system fixed to the reinforced steel core. For the elevators, to serve 110 stories with a traditional configuration would have required half the area of the lower stories be used for shaftways. Otis Elevators developed an express and local system, whereby passengers would change at "sky lobbies" on the 44th and 78th floors, halving the number of shaftways.


That is not what the following states for partial construction of the center core area.:

911review.org...

"Both the WTC 1 & WTC 2 towers had a rectangular cast concrete core structure formed into rectangular cells that had elevators and stairways in them."

That concrete was part of the center core area but the center core beams were definitely massive solid steel beam framing. What was used for concrete, was used to maintain stability, by avoiding to much flexing of the steel and loss of load bearing support, plus, seriously compromising the structure surrounding the center core area. The WTC was built to allow some flexing to a point, but not the point of losing load bearing capability or tearing away from center core area.

I have twice posted that steel tends to flex and lose support capability over tiime, from stress of mass, weight, air pressure, wind, traffic, settling, etc. It stands to reason reinforced concrete would have to be used as well, to avoid too much flexing and lost of support, particularly loading bearing support.

Could you please tell us the source from which your took the citation? If I edited it out by accident, I apologize.



posted on Dec, 16 2007 @ 05:25 PM
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Originally posted by jfj123

Originally posted by OrionStars
Tell a lumber supplier you are building an addition to your home. Tell them you want to try a new design. You need 2" x 4" rough framing lumber with hollow cores 1" x 3". Then further explain it is for use as primary load bearers. See what what is stated to you by whoever takes your order.


Wood and steel do not have the same dimensional bearing capacity so it's not really a fair question. Just my humble opinion.


Then you completely missed the point of my highly relevant analogy, with concentration on load bearing capability. No matter what type of building is built, it has to have solid primary and secondary load bearing capability. That was my point.

WTC was no exception to the rule contrary to what some people chose to opine, regarding the primary load bearing walls of the exterior framing on the WTC buildings. Those were not simply hollow steel tubes for highly obviously reasons. In fact, the wall frames were not actually full tubes at all. They were 3D exterior steel frames enclosing tubes of steel, which enclosed tubes of reinforced concrete. Then the extensions on each width end were tube shaped. That was so they could slide one tube end into another all the way up the building perimeter. Then they were, at the very least, welded together, and may well have then been bolted to further securely hold them together.

Would you use hollow core wood load bearers or not? Particularly, in consideration most wood rough framing is made out of softer pine and not some other harder wood. If not, why not? Is so, why so?

Is anyone confusing the steel facade for the exterior/perimeter steel and concrete load bearing wall frames? I am trying to give people the benefit of the doubt in case that is the problem.

[edit on 16-12-2007 by OrionStars]



posted on Dec, 16 2007 @ 05:28 PM
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reply to post by OrionStars
 


Actually most wood frame houses are made from Douglas Fir just FYI (At least here one the west coast)

However, strawman anologies aside, what other sources do you have for the exterior concrete structure of the WTC OTHER than that site?



posted on Dec, 16 2007 @ 05:30 PM
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reply to post by OrionStars
 


Yes, and they all interrelate, however, without mass and Velocity the other factors are null eh?



posted on Dec, 16 2007 @ 06:47 PM
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Originally posted by OrionStars
Could you please tell us the source from which your took the citation? If I edited it out by accident, I apologize.


Yes you edited out no problem, here it is again...

www.skyscraper.org...

But I suggest you do some research cause you'll find that the ONE article you keep referring to is the only one that will contradict the above link. That article doesn't even make sense structurally.

No masonry in the building other than floor pans, and the outer walls did not take the majority load, the central core did. In engineering terms this makes complete sense. If the outer wall held most of the vertical load when the towers swayed in high winds the vertical load holding capacity would be compromised, as all the vertical weight would be on a wall that was leaning out of true and more weight would be on the one side. If the central core takes most of the vertical weight and the outer wall were designed to take most of the lateral load it does away with that problem. That's why it was designed the way it was, very simple, very strong, and very effective.

They say the design was unique to buildings but the design methods used were not new to engineering, especially the outer mesh structure which is a design used where light-weight strength and safety are a factor. A design that will hold itself up when compromised, and it worked as it was supposed to. Until something took out the central core...

So there's no big mystery here as to how the buildings design should have acted.

No concrete was used to save weight. People who keep referring to hollow columns and light-weight design are not putting it into context. A hollow box or I beam/column is far stronger than a solid column would be. A hollow column will not bend and buckle easy as a solid one. It has nothing to do with weight but design. A lighter structure has NO LESS chance of globally collapsing than a heavy one, as long as the building is designed to carry it's weight plus a safety factor, 5x I believe for the towers. Heavier building, larger columns and less office space. Lighter structure, i.e. no concrete, smaller columns thus more floor space. It doesn't mean it's more likely to collapse than the heavier one as long as it's designed to carry the load.

[edit on 16/12/2007 by ANOK]



posted on Dec, 16 2007 @ 07:45 PM
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The core is the key, for sure. The fact that some incredible energy turned the core steel at bedrock and up to dust means a lot!! The molten pools of steel were from the core being melted from tens of thousands of degrees of something;what we don't know yet. But the proof is there.

The fact that the core turned to dust at the same rate as the rest of the Towers means that steel was unable to resist the energy, I believe a DEW;that seems the only way to achieve the results seen without a blast and radiation from a nuke type device. There WAS a huge blast way down low, as Rodriguez knows, and the 50 ton press that disappeared means a lot: Those things don't ' didappear ', they get tossed around by great force but to disappear? That is some force all right.

When we finally figure out the exact energy sourves used that day it will be fascinating I am sure: A mixture of several methods designed to get the results seen and leave enough wiggle room for deniability in case the media looked close: but no worries: they didn't. The 9-11 events are so filled with anomalies and screaming smoking gun holes that only a apathetic public and a controlled media could cover it up. Heaven help us all.



posted on Dec, 16 2007 @ 07:55 PM
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Originally posted by FredT
reply to post by OrionStars
 


Actually most wood frame houses are made from Douglas Fir just FYI (At least here one the west coast)

However, strawman anologies aside, what other sources do you have for the exterior concrete structure of the WTC OTHER than that site?


In my area, it is pine.

Since the emphasis was on load bearing not materials, perhaps you should consider checking the definition of strawman, before you accuse an opponent of making a logical fallacy, which he or she did not make.


The photo on this website is highly interesting. Those are individual and still tied together sections of perimeter exterior load bearing walls frames. For hollow steel tubes, those sections remains highly rigid. Just as if they were packed some type of reinforcement, which did not allow the tube sections to flex and lose shape.

vincentdunn.com...



posted on Dec, 16 2007 @ 08:27 PM
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reply to post by OrionStars
 


The article you linked failed to mention ANY concrete in the exterior of the structure in regards to the load bearing exterior. In fact based on the comments of the designers of the building, he is in error. The external wall of the WTC was designed for lateral wind loads the core for the cravity load of the building.

He also makes a case for the aluminium aircraft pretty much slicing through the building all the way to the core.

Im not sure what you want us to see in the picture. Im not seeing much steel encased in concrete



posted on Dec, 16 2007 @ 08:38 PM
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Originally posted by OrionStars

Then perhaps you missed the following when I posted it the first time?

911review.org...

Steel, no matter what temper, no matter what bracing is used, ends up with an overall flexation that exceeds design parameters for deformations and failures occur. These were fact I learned from a documentary in 1990 about the construction of the north tower. Yamsaki's decision making process was outlined and rejected core designs identified."


Okay, I know this was said a while back, and you've probably already been blasted for this already... but...

The mesh network of the steel framing is what was so unique about the structure. Forces applied to the structure via the wind would be compensated for on the lower floors, opposite the side being acted upon by a force (much like a giant spring). The inner core was a highly tempered steel that was very stiff, but brittle (got it from your own source you posted about the construction - your source is correct, you just have some strange interpretation). The exterior mesh was a softer steel that allowed for the flexing of the structure without risking damage to the structure. The central core provided rigidity and compression-load support. The exterior mesh balanced the core and provided support in the event of torsion (twisting/bending) generated by the winds.

The design allowed the WTC to be very light, yet strong for its mass. Even better, it allowed for more open floor-space that would better enable the businesses renting the space (and, ultimately, allow for more space to be rented out than a standard structure... which means more money for the same amount of space!).

The main drawback to the design is that it was pushed to its realistic limits with the scale of the structure. While not a really bad thing... this does come back around to bite you in the rear when something unplanned occurs... like a really big plane flying into the side of it.



posted on Dec, 16 2007 @ 11:59 PM
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Originally posted by ANOK

Originally posted by OrionStars
Could you please tell us the source from which your took the citation? If I edited it out by accident, I apologize.


Yes you edited out no problem, here it is again...

www.skyscraper.org...



Thank you. However, if you are referring to the following, which is the only reference I could find to the word hollow or tube, please note the brief words "structural model". That means the entire building not parts of the entire buildings:

"......the engineers employed an innovative structural model: a rigid "hollow tube" of closely spaced steel columns with floor trusses extended across to a central core. The columns, finished with a silver-colored aluminum alloy, were 18 3/4" wide and set only 22" apart, making the towers appear from afar to have no windows at all."

The citation is not referring to the materials or design of the exterior walls. It is referring to the design of the buildings. The twin towers literally did look like two hollow tubes reaching to the sky. It also indicated they would be free of internal primary load bearing reinforced concrete columns many commercial buildings, particularly high rises, had always used. Please note the placing of the words hollow tube in quotation marks. The words were not meant to be taken literally.




But I suggest you do some research cause you'll find that the ONE article you keep referring to is the only one that will contradict the above link. That article doesn't even make sense structurally.


From where did your source receive what you posted causing contradiction? My source used information from the designer and several people, who actually saw the WTC buildings constructed, and studied the construction at school. Therefore, you cannot conclude your source to be accurate and mine wrong. If anyone would know the materials used, it would be the designer/architect.




No masonry in the building other than floor pans, and the outer walls did not take the majority load, the central core did. In engineering terms this makes complete sense. If the outer wall held most of the vertical load when the towers swayed in high winds the vertical load holding capacity would be compromised, as all the vertical weight would be on a wall that was leaning out of true and more weight would be on the one side. If the central core takes most of the vertical weight and the outer wall were designed to take most of the lateral load it does away with that problem. That's why it was designed the way it was, very simple, very strong, and very effective.


Floor pans? Did you mean floors? Because I have never heard floors referred to as “floor pans”. I am aware the floors were 4” thick concrete slabs. However, contrary to what you chose to believe, that was not the only concrete used in the construction of the WTC buildings.

The core’s primary job for load was to take horizontal load. What was the horizontal load? Normally, the greatest horizontal load would be wind. So, the core’s primary load bearing job was to prevent the building from flexing until it broke apart and toppled over, with all that lightweight design, and no primary heavy, space consuming, inflexible reinforced load bearing internal concrete columns on every floor.. That was the core’s most important load bearing job - stabilizing the rest of the structure. The 24/7 daily stress was vertical. It wasn’t the core’s primary job to support all or a great deal of all that vertical weight, which ran from the core to the exterior walls. That was the primary job of the exterior wall frames, assisted by the depth of the concrete floor slabs,. the façade, and the center core.

Wind is, indeed, a heavy kinetic energy load to bear. But the wind wasn’t blowing with the same high kinetic energy 24/7. Contrary to a 24/7 weight and mass load, which remained fairly constant 24/7 for years.

To aptly compare whether the core or the exterior walls did the lion’s share of the load bearing , one must measure constants (exterior wall) to variables (center core) on amount of load bearing being done. The exterior walls were designed to take the lion’s share of vertical load bearing and some horizontal load bearing. The core was designed to take the lion’s share of stabilizing horizontal load bearing and some vertical load bearing. Physical laws demand balance lest failure occur.




They say the design was unique to buildings but the design methods used were not new to engineering, especially the outer mesh structure which is a design used where light-weight strength and safety are a factor. A design that will hold itself up when compromised, and it worked as it was supposed to. Until something took out the central core...

So there's no big mystery here as to how the buildings design should have acted.


Innovative means new design. Different. Never done like that before. When something is innovative, it cannot be aptly compared to anything else not like or almost like itself. The same laws of physics apply, and that is where any strong similarities may end. Unless, there are simply minor differences and nothing more. Are you certain the “….outer mesh structure…” is not simply a façade? What lies under outer design that make it substantially comparable to the rest of the inside structure? Yes, it does make a difference in comparing building designs.


No concrete was used to save weight. People who keep referring to hollow columns and light-weight design are not putting it into context. A hollow box or I beam/column is far stronger than a solid column would be. A hollow column will not bend and buckle easy as a solid one. It has nothing to do with weight but design. A lighter structure has NO LESS chance of globally collapsing than a heavy one, as long as the building is designed to carry it's weight plus a safety factor, 5x I believe for the towers. Heavier building, larger columns and less office space. Lighter structure, i.e. no concrete, smaller columns thus more floor space. It doesn't mean it's more likely to collapse than the heavier one as long as it's designed to carry the load.


[edit on 16/12/2007 by ANOK]

Do you have substantiation that validates a hollow column will not buckle as easily as a solid one?

What has weight to do with density strength (except something that is denser may weigh more)?

I will agree weight does not mean strength. For instance, if I have a 2 oz. steel ball in one hand and a 1 lb. book in the other,, I will bet my last dollar the lightweight steel ball is a great deal stronger than that 1 lb book. Yet, I would never say that hollow metal is stronger than the exact same spec solid metal, regardless of the difference in the weight. I would not say it because I could not prove it.

Now, if you said the same size hollow titanium (depending on core size) is stronger than solid steel, I might say this, “Well, maybe, but could you show me?” I have already been informed that titanium is 42% lighter and 3 times stronger than steel, when density is equal between the two metals.



posted on Dec, 17 2007 @ 12:25 AM
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All I can say Orion is do more research you have it all backwards...You keep insisting the central core took the lateral loads, this is not the case.

Why do you think the outer walls were a mesh design? So it could move laterally absorbing the loads.

Look at pictures of the building being built and you can quit clearly see NO concrete.

Yes I meant the floor slabs were concrete, sitting in steel pans, that was the only concrete.

Try to find any other reference for your claim, and then look for references for mine and see which one comes up more than once...


The tube in a tube nonsense came from a very simplified, and misleading, graphic of the buildings design here...


Now does that look like this...


I don't see any tubes, do you?



posted on Dec, 17 2007 @ 12:59 AM
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Originally posted by Aim64C

Okay, I know this was said a while back, and you've probably already been blasted for this already... but...

The mesh network of the steel framing is what was so unique about the structure. Forces applied to the structure via the wind would be compensated for on the lower floors, opposite the side being acted upon by a force (much like a giant spring). The inner core was a highly tempered steel that was very stiff, but brittle (got it from your own source you posted about the construction - your source is correct, you just have some strange interpretation). The exterior mesh was a softer steel that allowed for the flexing of the structure without risking damage to the structure. The central core provided rigidity and compression-load support. The exterior mesh balanced the core and provided support in the event of torsion (twisting/bending) generated by the winds.



Why do people keep using the word mesh? The word mesh strongly implies something very thin and flimsy. The structure of the WTC was anything but thin and flimsy. When I think of mesh, I think of netting, spider webs, etc. Things easily destroyed with very little effort.

The source I cited stated the center core columns were brittle? Which source was it? I have given several sources. I do not recall reading the center core columns were brittle. If they were brittle, they would not have been able to stabilize for wind loads pushing in and pulling out during structure flexing under high wind conditions, nor for their share of vertical loads (center of the roof and the inside edge floors). The inner core columns were massive at 54" x 22" each.

Softer steel? All the steel was high intensity steel with fire specs above the norm.

The "exterior mesh" balanced the core? Was it in danger of toppling if the outer structure was not there or what? Perhaps you need to research how the inner core was set below and above ground.


The design allowed the WTC to be very light, yet strong for its mass. Even better, it allowed for more open floor-space that would better enable the businesses renting the space (and, ultimately, allow for more space to be rented out than a standard structure... which means more money for the same amount of space!).


I recall posting basically the same information earlier.


The main drawback to the design is that it was pushed to its realistic limits with the scale of the structure. While not a really bad thing... this does come back around to bite you in the rear when something unplanned occurs... like a really big plane flying into the side of it.


How so? The North Tower did very well holding its own against any structural damage during that blowtorch type fire, in 1975, burning for at least 3 hours, and reaching 5 other floors through the center core. The twin towers were redundantly constructed to take the impact of a Boeing 707 unlike any other commercial buildings.

Since people plan to reconstruct the WTC, perhaps before they do, they should try this experiment first and allow the media to show it live to the public . Erect the entire core, not the entire structure, exactly as it was in the WTC up to a height of 110 stories. The core was a rectangle shape attached at all four corners. It will remain stable with nothing surrounding it.

Take a remote controlled 767, and set the same speed the "official” report states the alleged 767 was going when it impacted. There will be nothing to slow momentum before impacting the core. Then evaluate damage done to plane and core without resistance. That will give everyone a better idea of what possible damage the center core could have sustained with almost 80 feet of concrete, steel and office fixture resistance.

The side of impact was not one long unobstructed space. There were several internal walls dividing offices along the impact side running adjacent to the outside wall, and walls running parallel to the exterior wall. Outside the parallel wall was open space before meeting the center core of elevator shafts and stair wells. I seriously doubt they used wood framing for any interior walls.




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