Did You Know High Strength Steel Gives No Resistance to a Medium-Sized Aluminum Plane Going 450 MPH?
“Because of their unique design and the use of the so called “steel bearing wall” tube structural system, which as far as we know has never been used before or after its application in the WTC towers, the buildings essentially showed no resistance to the impact of a medium-sized plane flying into them at about 450miles per hour.”
(snip)
He also noted that designers chose to fabricate many of the building columns out of very high strength steel [90 ksi steel as opposed to the more typical 36-65 ksi steel]. “This is not allowed by the structural design codes then and is still notallowed in current codes,” he stressed. “But the World Trade Center did not need to obtain a permit from City Hall. Because of special status as Port Authority of New York and New Jersey, they could make such choices outside the prevailing codes.”
This choice, he argued, allowed builders to use less steel in the columns [two to three times thinner than typical columns] presumably to save cost.
But by using high strength steel and thin cross sections, he pointed out, on impact the plane was able to cut through the outside steel bearing wall and enter the building...
What will those wacky engineers come up with next???
posted by spooked at 4:55 PM
31 Comments:
http://www.ce.berkeley.edu/~astaneh/1-Research/wtc/wtc-studies.html
Clicking on the various links,one finds almost no content.
Here's him on that day, with it all figured out:
http://www.pbs.org/newshour/bb/military/july-dec01/structure_9-11.html
wait a sec...
is this *genius* stating that the wtc were built to the specs of an inferior design?
"""The simulation model shows the plane slicing right through the outer walls of the as-built building like it was a thin soda can,"Astaneh-Asl explained to the spellbound crowd.""
so he posited that the wtc was the equivalent of a soda can?
that is ludicrous - the wtc was built of MASSIVE steel!
box columns constructed of hardened STEEL 4" thick!
if anything "was a thin soda can" then it was a REAL 767!
he pointed out, ""on impact the plane was able to cut through the outside steel bearing wall and enter the building--delivering thousands of gallons of jet fuel to the interior. During the ensuing fire, he said, the thin outside columns of the steel bearing walls were quite vulnerable to the rapid rise of temperature""
the rapid rise of temperature?
how is it that the temperature was high enough to destroy the integrity of the massive steel but it wasn't hot enough to destroy this woman?
The columns were box beams. At that height, they were estimated to be about 1/3 inch (9.5 mm) thick. The walls forming the box beams were about 14 inches (356 mm) on each side.
http://ningens-blog.blogspot.com/2007/02/engineering-article-on-which-i-relied.html
(second page)
This paper modeled the columns using high-grade 1006 Steel, which is 350 MPa or 50 ksi. The paper found a 46% loss of kinetic energy to damage the columns and aircraft, without accounting for the resistance of the floors backing the external columns.
This cannot be "no resistance." Once again, the intelligence is fixed to match the video's policy.
Another policy result sought is to make the WTC unique so that expensive design changes are not deemed necessary:
“These structures were so unique that their collapse does not represent the performance expected of any other existing steel high-rise structure subjected to the same scenario,” he says.
He says the planes had 90,000 liters, or almost 24,000 gallons of fuel, which is the 767's capacity. They are said to have been about half full, or 45,000 liters.
At the base, the walls of the box beams were 5 inches thick, and presumably the box beams were virtually solid steel columns 14 inches square. The base of the buildings were far more massive, which doesn't address his assertion about the plane penetration but does make him not credible in saying the building pancaked down.
jet fuel can't vaporize skyscrapers, that's ALL there is to it...prove the nuclear demolition, and WE WIN...
www.wtcnuke.com
www.nucleardemolition.com
http://www.saunalahti.fi/wtc2001/evidence.htm
Good job on researching Hasteneh, Ningen-- he sounds like a grade A shill.
One thing I have not completly understand. When they say 9.5 mm, are they talking about each wall or plate of the column, or are the talking about inner + outer wall/plate of the column.
spooked did a post referring to the dimensions, incl. the thickness of each wall, of the columns in the wtc at the level where the plane-shaped hole was made - it's in his archives somewhere.
good luck finding it though!
25k gallons is the size of an average backyard below-ground swimming pool, so 12k gallons is not very much at all.
imagine that tiny amount of jetfuel/kerosene splashed through the giant steel wtc. it would certainly not destroy the integrity of any wtc steel - 1 gallon of kerosene did not even burn the paint off of my wheelbarrow.
Omar, I'm not sure if I understand your question, but my understanding is that column is a box formed by four plates 9.5 mm thick. The thickness of the plates varies from 125 mm at the base to 7.5 mm at the top, so they were slightly thicker in the South Tower where the plane hit lower. If they taper proportionally with each floor you might be able to calculate from 125 mm on the first floor to 7.5 mm at the top. The numbers may not be accurate but are the ones used in the Hoo Fatt article. I think they got their information from FEMA.
go here:
http://911research.wtc7.net/mirrors/guardian/WTC/wtc-demolition.htm
scroll down a little bit and there is a good diagram of the cross section of wtc perimeter columns.
so. does this mean that we are considering the physics of a real 767 hitting a wtc?
because if a real aluminum 767 with a plastic nosecone really hit a steel/concrete wtc @ 500mph with a force equivalent to X, that means that the steel/concrete wtc was also hitting the aluminum/plastic 767 with the same force equivalent to X.
a real aluminum/plastic 767 is not a depleted uranium tipped armor piercing projectile, but rather, a flying beercan.
it does ultimately boil down to aluminum/plastic vs. steel/concrete.
i am still awaiting the lesson in physics from sword_of_truth that is long overdue...
^ha.
About those fires-- I was watching the "Bob and Bri" "home" video of the WTC attack (which has no plane footage; it's on Revver.com). They show the north tower VERY early after the first hit. The fires were initally almost non-existent-- and only after 10 minutes or so, got fairly bad. This really doesn't make much sense from the standpoint of the plane splashing thousands of gallons of fuel into the building that started the fires. One of the first bad fires they filmed was a hot spot about two stories above the edge of the port wing hole-- which was a weird spot for a bad fire.
Here is the link for the video I was talking about:
http://one.revver.com/watch/?id=59686
I should say the fires really were not bad in WTC1 until much later, like 10am-- which is not really consistent with jet fuel beinbg the cause of the fires
real jetfuel would burn up as soon as it was sparked - are we to believe that some burning carpet or linen closets or something were responsible for all of that black smoke from the wtc1? maybe it was the paper towels in the bathrooms!
for that matter, black smoke denotes either a low temp smoldering oxygen starved fire or a "smudge-pot" (fuel/oil mix) anyway - neither of which would be hot enough to compromise the integrity of any wtc steel - especially after only 1 hour total of smoldering.
"raging inferno"?
the ghost of edna cintron begs to differ.
raising a cerveza in the direction of pinch & assoc!
^ha.
Ningen: Ok. Thank you.
So, they are saying that each plate is 9.5mm.
And about ksi steel then nist say that most of the perimeter columns at impact side was 55 and 65 ksi steel http://wtc.nist.gov/NISTNCSTAR1-3A.pdf (p.13-14)
But about it all... then I dont belive one second that all the plane can simply "enter" the building as can be seen in the videos and this famous animation.
Something strange is going on here imo.
Omar, I like to use this quote by MIT professor Tomasz Wierzbicki, crash expert:
To the casual observer, it would appear that the facade of the Twin Towers did not offer any resistance at all, and that the plane's wings and fuselage slice through the exterior columns as if they were made of cardboard. . . How was it possible that the relatively weak, light, and airy airframe damaged the apparently heavy lattice of high strength steel columns? The devastating result of this encounter came as a surprise to the engineering and scientific community or at least to the present authors.
Wierzbicki and Teng, How the airplane wing cut through the exterior columns of the World Trade Center, Int'l J. of Impact Engineering 28 (2003)601-625, at 602.
This paper purports to prove what they begin by saying is absurd. Their common sense comports with mine, and I'm going with it.
Looking at the link posted by anonymous 12:13 above,
http://911research.wtc7.net/mirrors/guardian/WTC/wtc-demolition.htm
I wonder if each plate of the beams was really the same thickness. I've just been citing the model of Karim and Hoo Fatt, which might not be realistic.
Yes. Exactly. I have wonder about the same too. (that is, if "each plate of the beams was really the same")
It is all so unclear... and weird.
(And what about the swaying and damping system in the towers... it must have eat up some energy from the hit (imo)
the sides of the box columns were thicker than the front and back, as explained here.
For the south tower hit, we are talking about 13/16 inches of steel on two 14 inch sides per column that the plane wings/tail/fuselage would have to transverse.
Thanks for pointing this out, Spooked and Omar. This makes more sense intuitively, as 1/4 inch steel is not very thick even that high up, and it's hard to see how a column with walls that thin could bear heavy loads.
I now realize that both the Wierzbicki/Teng paper and the Hoo Fatt paper modeled the box beams as 9.5 mm = .37" = 6/16" on each side. These are only slightly thicker than the front and back plates (which they call "flanges") and the side plates (which they call "webs."
The webs, then, are almost an inch wide and 14 inches deep. Shearing of these would have to expend more energy than if the webs were half as thick. I had assumed that they had reasonably approximated actual conditions.
This may be another of the assumptions that Wierzbicki used to overcome his common sense understanding that the video was not realistic.
I'll post something later about this with relevant pages from the papers. The pictures show symmetrical box beams, which is not realistic. I'll have to try and calculate, but I don't see that 6/16" on four sides is an average of 4/16" flanges and 13/16" webs, and even if it were, more thickness in the sides should make the column harder to shear because the sides are so deep.
Thanks to anon-12:13 also for the link to pictures of the columns.
I would appreciate any more information people have on this. I will attribute all contributions in the blog post I write on this.
Is this as significant as I think it is? The Karim/Hoo Fatt paper showed a 46% loss of the plane's initial kinetic energy just from penetration of the external columns. Shouldn't the thicker webs result in higher loss of kinetic energy?
I have come to doubt whether these models prove that the videos are faked, especially because my ability to understand them is so limited, but I figure I might as well keep looking at the assumptions they make.
I had assumed that they had reasonably approximated actual conditions
nin you are much too forgiving...
these people are supposed to be scientific/engineering experts!
when they resort to manipulating data in order to justify a preconceived (impossible!) scenario they should be considered as beneath contempt.
The webs, then, are almost an inch wide and 14 inches deep.
and that is just the PERIMETER columns - imagine the composition of a CORE column!
how long would it take to cut thru the webs or sides of each box column with a specialized cutting torch?
a very long time indeed! (take a welding class.)
certainly the smooth rounded lightweight plastic nosecone of a REAL lightweight aluminum 767 could not cut thru such a massive piece of steel - much less a great number of such massive pieces of steel...
still waiting for the definitive lesson in physics. (long overdue now sword!)
^h
You're right, ha, but I also pity them.
"much less a great number of such massive pieces of steel..."
This is an important point, also, I think. Wierzbicki looked only at the impact of one part of the wing on one column. Hoo Fatt explicitly said this is wrong. In a debate with me at 911blogger, Greg Jenkins said that Hoo Fatt is wrong - Wierzbicki multiplied the individual losses of kinetic energy for one column times the number of columns. That appears to be correct. However, I think Hoo Fatt was also correct - you can't simply multiply like that. My rough understanding is that you have ot spread the impact. Wierzbicki was created a projectile out of one part of the wing and assuming all the energy activated only the local inertia, and not the global inertia of the building or at least the surrounding columns. Hoo Fatt accounted for that, and even adding the mass of the fuel which Wierzbicki had included in his model, found a much higher loss of kinetic energy.
I think the thicker side walls of the columns would mean even more dispersion of energy, so Hoo Fatt's model is also wrong. Not to mention she does not even include the floors behind the external columns.
In short, ha's (and Wierzbicki's) common sense is correct - an aluminum nose cone could never cut through all that steel. Even the engine and fuel-laden midsection of the wing would not cut through, at least not with a grossly obvious impact that also affected the tail of the plane.
Even a toe-sucking fucktard like me can see that.
"Even a toe-sucking fucktard like me can see that."
Whoops, wrong thread. The morning shift called us "Spook's toe suckers." Funny how the suckers of the rulers' toes are not hear with their mindless insults.
That would be "Spooked." Have I ever told you what an awesome name that is?
There I go again, sucking Spooked's toes.
Correction to 8:35:
"even adding the mass of the fuel which Wierzbicki had NOT included in his model,"
FYI, high-strength steel is far more expensive than "regular" steel. Typically, it is only used when space (steel-section) or mass reduction are more important than the higher cost.
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