How Does Aluminum Cut Steel?

reply to post by Bilk22

....even discounting the idea that a novice was able to navigate a sophisticated plane in the manner you suggest when professionals have said it would be virtually impossible even for trained pilots.

Merely steering the jet is so easy, a ten-year old could do it......"sophistication" does not apply to what's termed in the vernacular basic "stick and rudder" flying (although, on a modern jet, even easier than a smaller "simpler" airplane....the rudder is not even needed, it is taken care of automatically by the always-on yaw dampers).

Oh, and there is, by my count, less than the fingers on one hand number of "professionals" who have claimed it to be "virtually impossible".....that old canard has been floating around on the Internet for many years. It's a crock.

You made a claim that they were traveling in excess of 400mph and actually approaching 500mph as a result of the effects of gravity plus thrust. Well look a videos of the event. They are traveling horizontal to the ground and not as you posited. Additionally, if it was indeed as you say, the plane was put into a steep dive to help accelerate to the speed, experts have said they would have had difficulty maintaining control. However we know from video evidence the planes were horizontal to the ground well before impact. None of what you suggest hold water.

Originally posted by PluPerfect
reply to post by Bilk22

 

....even discounting the idea that a novice was able to navigate a sophisticated plane in the manner you suggest when professionals have said it would be virtually impossible even for trained pilots.

Merely steering the jet is so easy, a ten-year old could do it......"sophistication" does not apply to what's termed in the vernacular basic "stick and rudder" flying (although, on a modern jet, even easier than a smaller "simpler" airplane....the rudder is not even needed, it is taken care of automatically by the always-on yaw dampers).

Oh, and there is, by my count, less than the fingers on one hand number of "professionals" who have claimed it to be "virtually impossible".....that old canard has been floating around on the Internet for many years. It's a crock.

As for the "crock" part of your post, what makes you expert enough to make that claim? Maybe you should start here and do some reading. 9-11 Research

Originally posted by PluPerfect
reply to post by Bilk22

 

....even discounting the idea that a novice was able to navigate a sophisticated plane in the manner you suggest when professionals have said it would be virtually impossible even for trained pilots.

Merely steering the jet is so easy, a ten-year old could do it......"sophistication" does not apply to what's termed in the vernacular basic "stick and rudder" flying (although, on a modern jet, even easier than a smaller "simpler" airplane....the rudder is not even needed, it is taken care of automatically by the always-on yaw dampers).

Oh, and there is, by my count, less than the fingers on one hand number of "professionals" who have claimed it to be "virtually impossible".....that old canard has been floating around on the Internet for many years. It's a crock.

Originally posted by Bilk22
However we know from video evidence the planes were horizontal to the ground well before impact.

UA 175 lost about 1400 ft in the last 12 seconds. All the videos of UA 175 are laid out to form a 3D model. The altitude chart is at 4:30

This is a truther video.

Originally posted by Bilk22

Sorry wrong answer. They cannot be looked at separately. They're are part of a system just as the wings are part of a system. The columns didn't stand and thus fall on their own. Try again.

I disagree as, I assume, do the authors of the article. It depends on what your question is. Did you read the article? The authors were looking specifically at how the exterior steel columns of the WTC likely responded to an impacting airplane wing. The question CAN be looked at separately, as long as conclusions are not generalized beyond the scope of the specific research, which, in this case they're not. It's meant to be a very small contributing piece to a much larger puzzle. Your point about the columns and wings being parts of larger systems is obvious and the authors of the article are not denying this nor ignoring it. In case you missed it, here's the abstract to the article:

The problem of the airplane wing cutting through the exterior columns of the World Trade Center is treated analytically. The exterior columns are thin-walled box beam made of high strength steel. The complex structure of the airplane is lumped into another box, but it has been found that the equivalent thickness of the box is an order of magnitude larger than the column thickness. The problem can be then modeled as an impact of a rigid mass traveling with the velocity of 240 m/s into a hollow box-like vertical member. The deformation and failure process is very local and is broken into three phases: shearing of the impacting flange; tearing of side webs; and tensile fracture of the rear flange. Using the exact dynamic solution in the membrane deformation mode, the critical impact velocity to fracture the impacted flange was calculated to be 155 m/s for both flat and round impacting mass. Therefore, the wing would easily cut through the outer column. It was also found that the energy absorbed by plastic deformation and fracture of the ill-fated column is only 6.7% of the initial kinetic energy of the wing.

Originally posted by lunarasparagus

Originally posted by Bilk22

Sorry wrong answer. They cannot be looked at separately. They're are part of a system just as the wings are part of a system. The columns didn't stand and thus fall on their own. Try again.

I disagree as, I assume, do the authors of the article. It depends on what your question is. Did you read the article? The authors were looking specifically at how the exterior steel columns of the WTC likely responded to an impacting airplane wing. The question CAN be looked at separately, as long as conclusions are not generalized beyond the scope of the specific research, which, in this case they're not. It's meant to be a very small contributing piece to a much larger puzzle. Your point about the columns and wings being parts of larger systems is obvious and the authors of the article are not denying this nor ignoring it. In case you missed it, here's the abstract to the article:

The problem of the airplane wing cutting through the exterior columns of the World Trade Center is treated analytically. The exterior columns are thin-walled box beam made of high strength steel. The complex structure of the airplane is lumped into another box, but it has been found that the equivalent thickness of the box is an order of magnitude larger than the column thickness. The problem can be then modeled as an impact of a rigid mass traveling with the velocity of 240 m/s into a hollow box-like vertical member. The deformation and failure process is very local and is broken into three phases: shearing of the impacting flange; tearing of side webs; and tensile fracture of the rear flange. Using the exact dynamic solution in the membrane deformation mode, the critical impact velocity to fracture the impacted flange was calculated to be 155 m/s for both flat and round impacting mass. Therefore, the wing would easily cut through the outer column. It was also found that the energy absorbed by plastic deformation and fracture of the ill-fated column is only 6.7% of the initial kinetic energy of the wing.

And yet those same wings couldn't even put a dent or an imprint on the wall of the Pentagon.

You can't have it both ways, Solarbroccoli or whatever your name is. And that is one creepy avatar.

reply to post by SimontheMagus

Not sure what your point is. What do the exterior steel box columns of the WTC have to do with the pentagon?

Originally posted by lunarasparagus
reply to post by SimontheMagus

 

Not sure what your point is. What do the exterior steel box columns of the WTC have to do with the pentagon?

Stop playing games. I'm typing in English. Are you reading in Swahili?

Those same hollow aluminum wings that somehow sliced through those exterior box columns couldn't even manage to leave a visible imprint on the wall of the Pentagon. They can't be Superwings from Krypton in New York and magically vaporizing gingerbread wings in Washington that blew away in the breeze. Pick one and polish that turd, but you can't have both.

Originally posted by SimontheMagus

Originally posted by lunarasparagus
reply to post by SimontheMagus

 

Not sure what your point is. What do the exterior steel box columns of the WTC have to do with the pentagon?

Stop playing games. I'm typing in English. Are you reading in Swahili?

Those same hollow aluminum wings that somehow sliced through those exterior box columns couldn't even manage to leave a visible imprint on the wall of the Pentagon. They can't be Superwings from Krypton in New York and magically vaporizing gingerbread wings in Washington that blew away in the breeze. Pick one and polish that turd, but you can't have both.

You're typing English, but your grossly oversimplified logic indicates you've spent more time reading comic books than anything pertaining to the real world (hence the Krypton allusion). It seems obvious, but I'll give you a hint--the walls of the Pentagon comprised thick steel-reinforced concrete and brick, making them significantly more robust than the thin-walled steel box-tube lattice of the WTC. Do you think there might be a difference in how the impacting wings of a plane would affect such totally different kinds of structures?

Think about it. I know you can put it together. I believe in you.

reply to post by Bilk22

If you're interested in a more comprehensive analysis of the aircraft impact damage to the WTC, try this one published by MIT (co-authored by T. Wierzbicki who co-wrote the first article I posted):

Aircraft Impact Damage

Originally posted by lunarasparagus

Originally posted by SimontheMagus

Originally posted by lunarasparagus
reply to post by SimontheMagus

 

Not sure what your point is. What do the exterior steel box columns of the WTC have to do with the pentagon?

Stop playing games. I'm typing in English. Are you reading in Swahili?

Those same hollow aluminum wings that somehow sliced through those exterior box columns couldn't even manage to leave a visible imprint on the wall of the Pentagon. They can't be Superwings from Krypton in New York and magically vaporizing gingerbread wings in Washington that blew away in the breeze. Pick one and polish that turd, but you can't have both.

You're typing English, but your grossly oversimplified logic indicates you've spent more time reading comic books than anything pertaining to the real world (hence the Krypton allusion). It seems obvious, but I'll give you a hint--the walls of the Pentagon comprised thick steel-reinforced concrete and brick, making them significantly more robust than the thin-walled steel box-tube lattice of the WTC. Do you think there might be a difference in how the impacting wings of a plane would affect such totally different kinds of structures?

Think about it. I know you can put it together. I believe in you.

edit on 12-6-2012 by lunarasparagus because: (no reason given)

I see. So you're still polishing both turds. I knew you would do that.

Originally posted by SimontheMagus

I see. So you're still polishing both turds. I knew you would do that.

No. Get it right. It's not me. Both "turds" are being "polished" by Tomasz Wierzbicki and colleagues, MIT Professor of Applied Mechanics and Director of MIT's Impact and Crashworthiness Laboratory.

Who supports your planet Crypton comic book theory?

Originally posted by lunarasparagus

Originally posted by SimontheMagus

I see. So you're still polishing both turds. I knew you would do that.

No. Get it right. It's not me. Both "turds" are being "polished" by Tomasz Wierzbicki and colleagues, MIT Professor of Applied Mechanics and Director of MIT's Impact and Crashworthiness Laboratory.

Who supports your planet Crypton comic book theory?

Your own words prove your ineptitude. Why is concrete "reinforced" with steel to begin with? Which of the two is stronger? And as for that steel that reinforces concrete, it's not 18 inch beams we're talking about, it's rods usually about an inch or two in diameter.

Why not try a little experiment? Home Depot or Lowe's or whatever do it yourself outlet sells homeowner-type power-washers for as little as $99.95..... or borrow one from your neighbor. Get yourself a slab of steel-reinforced concrete. Set the nozzle on the washer to maximum concentration and see how easy it is to carve your initials into it. Keep it there a few seconds and see how fast you get down to that steel.

Now try the same thing with a steel beam. It doesn't even have to be anything near what was in the WTC exterior. Let us know how you're doing every 6 months or so.

reply to post by SimontheMagus

You didn't answer my question. Can you name a credible professional in applied physics or engineering who has published work in a professional/peer-reviewed journal who has posited the claims you are making? Which are, from what I gather, either that the wings of the planes that struck the WTC would not have been able to shear the steel perimeter columns--or, that if they had (krypton wings), they would have also penetrated the reinforced concrete wall of the pentagon (because reinforced concrete is no more massive/robust than a steel box-tube lattice).

In other words, can you support your claim with published research?

reply to post by SimontheMagus


This is a lie:

Those same hollow aluminum wings ...(snip)... couldn't even manage to leave a visible imprint on the wall of the Pentagon.

Close-up photos show the marks made by the outer lengths of the wings (outboard of the engines, and the more robust wing spars that support them) on the Pentagon facade stones.

Anyone who did the proper research would have known this.

Originally posted by lunarasparagus

Originally posted by SimontheMagus

I see. So you're still polishing both turds. I knew you would do that.

No. Get it right. It's not me. Both "turds" are being "polished" by Tomasz Wierzbicki and colleagues, MIT Professor of Applied Mechanics and Director of MIT's Impact and Crashworthiness Laboratory.

Who supports your planet Crypton comic book theory?

Show us specifically where Wierzbicki proved in a laboratory that hollow aluminum wings can slice through steel beams equivalent to those on the perimeter of the towers without even slowing down or leaving any trace of them behind to rain down on the street below. Also show us where he proved in a laboratory that those same hollow wings that had enough mass to slice those steel beams like a hot knife through butter were lacking enough mass to put a very noticeable imprint in those concrete walls of the Pentagon. If you can do that, I'll deal with it and formulate a response.

In the meantime, chew on this for awhile....
We Have Some Holes In The Plane Stories

www.911hoax.com...

What 911 Should Have Looked Like

nomoregames.net...

Originally posted by PluPerfect
reply to post by SimontheMagus

 

This is a lie:

Those same hollow aluminum wings ...(snip)... couldn't even manage to leave a visible imprint on the wall of the Pentagon.

Close-up photos show the marks made by the outer lengths of the wings (outboard of the engines, and the more robust wing spars that support them) on the Pentagon facade stones.

Anyone who did the proper research would have known this.

Show us these close-up photos with these wing marks where we can clearly see that they are wingmarks, not some photo where I have to take mescaline and '___' to see it.

How about the WTC's Manager of the Construction and Project Management, does his opinion matter? Or do you experts know more than he did about how the WTC was built?

In the following interview clip, which took place inside of the Twin Towers on January 25, 2001, and aired on the 7th Season of the History Channel's Series "Modern Marvels" on June 25, 2001, Frank A. DeMartini, Manager, WTC Construction and Project Management, explains how the Twin Towers were "designed" to withstand the impact of a "fully-loaded Boeing 707." He also goes on to say that each of the Twin Towers would "probably sustain multiple impacts of jetliners because this structure is like the mosquito netting on your screen door: this intense grid; and, the jet plane is just a pencil puncturing this screen netting; it really does nothing to the screen netting."

It is interesting to note that the planes that slammed into the Twin Towers were Boeing 767s, which have a maximum take-off weight of 300,000 pounds, slightly less than the 330,000-pound maximum of the Boeing 707, making them slightly smaller than the planes the architects designed the Twin Towers to withstand the impacts of.

www.youtube.com...

Originally posted by Blue_Jay33
It has always troubled me how a lighter Aluminum alloy cut the external steel grid of the WTC like a hot knife going through butter. Watching the pictures of construction in the 70's those things were large and strong, the fascade was weak yes, but the steel behind it was thick and strong.
When you watch the second plane hit and go through it so easily, it just doesn't seem possible. I know some people will say kinetic energy did it.
But shouldn't the wings have snapped off like in other plane accidents.
This part of 9/11 baffles me. Thoughts?

I've seen plenty of carbon fiber and aluminum framed race cars deform and Rip through steel barricades on race tracks pretty easily. Just because it's aluminum doesn't mean it has zero mass.

Don't the engines contain large amounts of titanium components also?

Originally posted by SimontheMagus

Show us specifically where Wierzbicki proved in a laboratory that hollow aluminum wings can slice through steel beams equivalent to those on the perimeter of the towers without even slowing down or leaving any trace of them behind to rain down on the street below. Also show us where he proved in a laboratory that those same hollow wings that had enough mass to slice those steel beams like a hot knife through butter were lacking enough mass to put a very noticeable imprint in those concrete walls of the Pentagon. If you can do that, I'll deal with it and formulate a response.

Wierzbicki used a mathematical model which was informed by experiments he had done in a laboratory. Again you can obtain the article here:

His conclusion states:

In this paper, we have analyzed the sequential failure of a typical exterior column of the World Trade Center Towers subjected to the impact of the airplane wing traveling at 240 m/s. It was found that the fracture process started immediately and continued as plate tearing on the side webs to be completed as tensile/shear fracture on the rear flange. In each stage, the resisting forces arising from plastic deformation and fracture were calculated and the time history of the velocity of the impacting wing section was determined.

The minimum impact velocity to cause fracture was determined from Eq. (24) to be 155 m/s. Should the aircraft be traveling not at a cruising speed but at a much lower take-off or landing speed of 200 mph (about 100 m/s), then the exterior columns would appear to have deflected the wings without fracture.

It is concluded that the process of wing cutting through the exterior columns dissipated only 1.139 MJ of energy. This constitutes only 6.7% of the initial kinetic energy of the wing. The remaining 93.3% of the kinetic energy was then transferred into the interior of the building causing fatal damage to the floors and core structure. The present analysis introduced a substantial correction to the earlier estimate of the energy required to shear the column reported in Ref. [1] but in each case the energy to break the airplane wing through the exterior facade of the Twin Towers is insignificant.

The present analysis also suggested that the exterior column would be able to stop the airplane wing or at least prevent a local shear failure if the average flow stress of the material is increased by a factor of two. Thus, had the plane hit the base of the Towers which were made of high strength steel with the yield stress of s y ¼ 700 MPa; the airplane might have been deflected by the exterior walls.

If that's not enough, another article was published in the JOURNAL OF ENGINEERING MECHANICS, Karim M, Fatt M., OCTOBER 2005]: Impact of the Boeing 767 Aircraft into the World Trade Center (get it HERE) which critiqued and broadened Wierzbicki's research using LS-DYNA computer simulation. They found some differences in resulting data, but confirmed Wierzbicki's general findings, concluding that:

1. At the top speed of the aircraft  240 m/s, about 46% of the initial kinetic energy of the aircraft was used to damage the columns and the aircraft. The residual impact velocity of the aircraft after the penetration was 171 m/s.

2. The residual impact velocity and kinetic energy increase with the percentage of full fuel tank present in the wing. Thus, the assumption of a full tank of fuel is the worst impact scenario, although the residual velocity and kinetic energy does not vary much with the amount of fuel if the tanks are over 65% full.

3. Assuming a full tank of fuel, we found that:
• the minimum impact velocity of the aircraft to penetrate the exterior columns was 130 m/s and
• if the column thickness is more than 20 mm, the aircraft wings and fuel tanks would not penetrate the exterior columns of the WTC.

So tell me again who the credible professionals are who have published research contradicting Wierzbicki's research? The ones who assert the "wings from Krypton" theory.