Hardfire: Physics of 9/11

[Furcifer]

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I have not seen anywhere that explains how the energy to produce that movement was accounted for in relation to the structural damage caused by the impact. I would be most interested in someone specifying that in the NCSTAR1 report.

Well a quick googling reveals this to be an old rehash of the Gordon Ross BS about seismic data or some non sense. I can't download NCSTAR 1-5, which is from what I gather where this calculation of 12 in. movement on the 71st floor comes from. I thought it was calculated from the natural frequency of the building due to wind loads etc. This whole conversation seems vaguely familiar, and yet they always are aren't they.

Your model shows nothing about the impact of the planes and the induced oscillation. Nor does it show anything about how a relative deviation in the mass would do anything.

It does show you have pretty nice hardwood floors, which I suspect is the reason you don't really want all those washers hitting the floor.

 

[Furcifer]

I apologise for not reading over all of the previous pages but I am unsure what you are asking for here. Other than small ejecta and fuel, all of the plane's energy was expended into the towers?

Could you be more precise?

I think he's saying there was a certain amount of dampening. Not all of the energy went into deformation, but instead was dissipated as heat and sound.

From what I remember, the amount of chemical energy released by the fuel exploding was far greater than what would have been absorbed and not gone into deformation.

He's then made this quantum leap into assuming the mass (the exact mass) of the perimeter panels has something to do with this? I don't know I really can't connect the dots, nor can he.

He definately feels he's onto something here though.

 

[beachnut]

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Since I built a model and demonstrated the effect of impacts I feel there is a lot I don't need to say. I showed it.

http://www.youtube.com/watch?v=z0kUICwO93Q

Obviously the base did not move. On the real building I would expect every thing above the 20th floor moved to a significant degree. Since the NIST says the 70th level moved 12 inches that means the floor slab the core columns and beams AND THE PERIMETER COLUMNS AND SPANDRELS. I have not seen anywhere that explains how the energy to produce that movement was accounted for in relation to the structural damage caused by the impact. I would be most interested in someone specifying that in the NCSTAR1 report.

I have communicated with a number of people over the years that have claimed various stuff was in the NIST report but than they didn't say where it was. Ron Wieck played that game with me once saying, "Did you look here?" And then provides a link to a 200 page report. I provide links page numbers and quotes when I say something is in the NCSTAR1.

psik

Did you miss it in NIST? Should you read the 100,000 plus pages again? What did FEMA say? There are sources talking about how the building handled lateral loads. Research is hard; hang in there.

Would the physics of Karate help you make better models? http://www.howeverythingworks.org/journal/Article1.1.pdf
http://www.phys.ttu.edu/~cmyles/Phys5306/Papers/2004/Physics of Martial Arts.doc

 

[psikeyhackr]

Well a quick googling reveals this to be an old rehash of the Gordon Ross BS about seismic data or some non sense. I can't download NCSTAR 1-5, which is from what I gather where this calculation of 12 in. movement on the 71st floor comes from. I thought it was calculated from the natural frequency of the building due to wind loads etc. This whole conversation seems vaguely familiar, and yet they always are aren't they.

Your model shows nothing about the impact of the planes and the induced oscillation. Nor does it show anything about how a relative deviation in the mass would do anything.

It does show you have pretty nice hardwood floors, which I suspect is the reason you don't really want all those washers hitting the floor.

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What are you talking about? The last link I posted was not the one with the washers?

http://www.youtube.com/watch?v=z0kUICwO93Q

Both videos have the same opening but the titles are different. The Mass Interaction Test is impacts against a tower producing oscillations. It is a private joke because I applied to MIT and got an interview but not accepted.

These are location talking about oscillation in relation to the impact on the south tower:

south tower impact and oscillation.

NCSTAR1-2.pdf page 142

Moire analysis of time dependent oscillation amplitude.

NCSTAR1-5A_AppxH-M.pdf page 181

Appendix K

NCSTAR1-5A_chap_1-8.pdf page 198

NCSTAR1CollapseofTowers.pdf page 88 & 232

There are 63 instances of oscillation in 9 documents. The majority relate to the wind analyses of the buildings. I don't see any discussion of the computation of the amount of energy from the impact that started the oscillation.

psik

 

[Furcifer]

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What are you talking about? The last link I posted was not the one with the washers?

Oops I suppose you blew your budget on floor wax, none left for the opening credits.

I don't have audio so I'm not sure what's going. I can see you have an elastic collision. That's not going to be helpful in demonstrating what actually happened. Likewise your "plane" is massive, that's not going to be helpful either. And your distribution of mass is way off, it didn't vary anywhere near what you are suggesting it did.

There's also the issue that your model tower seems very elastic, I'm not sure the towers were as flexible as that. All these things present a gross misrepresentation of what actually happened, all of which seem to favour your particular interpretation of events.

I don't see any discussion of the computation of the amount of energy from the impact that started the oscillation.

I think what you really want is the calculation of how much energy was dissipated by the oscillation. The rest would have gone into destroying various structural components. Unless I'm missing something?

 

[psikeyhackr]

Oops I suppose you blew your budget on floor wax, none left for the opening credits.

I don't have audio so I'm not sure what's going. I can see you have an elastic collision. That's not going to be helpful in demonstrating what actually happened. Likewise your "plane" is massive, that's not going to be helpful either. And your distribution of mass is way off, it didn't vary anywhere near what you are suggesting it did.

There's also the issue that your model tower seems very elastic, I'm not sure the towers were as flexible as that. All these things present a gross misrepresentation of what actually happened, all of which seem to favour your particular interpretation of events.

I think what you really want is the calculation of how much energy was dissipated by the oscillation. The rest would have gone into destroying various structural components. Unless I'm missing something?

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Can you comprehend the difference between a DEMONSTRATION OF PRINCIPLE and a scale model?

The WTC was supposed to sway 3 feet at the top in a 150 mph wind. That was only 1.5% of its width. My model can sway a little more than 100% of its width at the top. If the model only swayed 1.5% it would be nearly impossible to see in the video. If a real skyscraper swayed that much it would probably collapse.

The airliner was only 1/2 of 1/10th of 1% the mass of the tower. I would have had to use something like a 22 bullet to have something small with a high velocity. It would damage the tower every time and I would hve to rebuild it for every variation.

The behavior of the tower changed with mass and its distibution which was the entire point. To show that that information about the towers is necessary for analyzing the 9/11 incidents. Which we do not have after 7.5 years.

psik

 

[BigAl]

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The airliner was only 1/2 of 1/10th of 1% the mass of the tower. I would have had to use something like a 22 bullet to have something small with a high velocity. It would damage the tower every time and I would hve to rebuild it for every variation.

psik

Fired from a pistol, the plane would outrun the bullet. The planes were traveling "fast as a 22" within the accuracy of your toy model.

500MPH is about 722ft/sec and a classic .22 round is only slightly supersonic when fired from a rifle. From a pistol, the plane wins.

You really haven't figured out the scale thing.

 

[Furcifer]

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Can you comprehend the difference between a DEMONSTRATION OF PRINCIPLE and a scale model?

I thought I pointed out the principles I saw demonstrated. An elastic collision, coefficient of restitution, pressure and stiffness constant. All of which were grossly inaccurate for the purposes of demonstrating what happened.

.
The WTC was supposed to sway 3 feet at the top in a 150 mph wind. That was only 1.5% of its width. My model can sway a little more than 100% of its width at the top. If the model only swayed 1.5% it would be nearly impossible to see in the video. If a real skyscraper swayed that much it would probably collapse.

So if you have a 150mph wind, the surface area of one face of the WTC and the amount of sway you could probably work out a stiffness constant to model the tower as a spring. Knowing the height of the towers and the location of the impact, the mass and velocity of the plane, you could then predict the oscillation of the tower after an application of force. Even without knowing the mass of the tower or the perimeter. I mean if you wanted to of course.

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The airliner was only 1/2 of 1/10th of 1% the mass of the tower. I would have had to use something like a 22 bullet to have something small with a high velocity. It would damage the tower every time and I would hve to rebuild it for every variation.

Non-destructive testing is so difficult to model when you are faced with an event that was anything but.

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The behavior of the tower changed with mass and its distibution which was the entire point. To show that that information about the towers is necessary for analyzing the 9/11 incidents. Which we do not have after 7.5 years.
psik

No, in these regards the behaviour of the tower and the mass distribution was constant for 30 years. Actually, the behaviour of the tower was known before is was built. At least theoretically. From what I remember, this was tested and confirmed several times during the life of the towers, most recently in the mid 90's.

 

[aggle-rithm]

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But was it enough to make the building collapse?

Evidently!

ETA: The fire helped, as well.

 

[rwguinn]

I thought I pointed out the principles I saw demonstrated. An elastic collision, coefficient of restitution, pressure and stiffness constant. All of which were grossly inaccurate for the purposes of demonstrating what happened.


So if you have a 150mph wind, the surface area of one face of the WTC and the amount of sway you could probably work out a stiffness constant to model the tower as a spring. Knowing the height of the towers and the location of the impact, the mass and velocity of the plane, you could then predict the oscillation of the tower after an application of force. Even without knowing the mass of the tower or the perimeter. I mean if you wanted to of course.



Non-destructive testing is so difficult to model when you are faced with an event that was anything but.



No, in these regards the behaviour of the tower and the mass distribution was constant for 30 years. Actually, the behaviour of the tower was known before is was built. At least theoretically. From what I remember, this was tested and confirmed several times during the life of the towers, most recently in the mid 90's.

Amazingly enough, if you get the deflection at various floors under a wind force (also available-I recall reading it, but cannot remember where), then model a cantelever with distributed load (wind load), you can, from the latter, get the distributed stiffness of the structure.
Incorporating the stifness into the model, you can then get the mass distribution from the eigen solution of the distributed stiffness model with distributed mass (take the natural frequency, which is known and in the NIST report (about 1/11 Hz IIRC) and converge on a solution)
It will be reasonably accurate...
An interesting problem, mostly book-keeping, and totally pointless in the long scheme of things.

 

[psikeyhackr]

Evidently!

ETA: The fire helped, as well.

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If you don't know the distribution of steel and concrete and don't understand the conservation of momentum.

But then you can't apply the conservation of momentum if you don't know the distribution of steel and concrete.

It's the old, "Don't confuse me with the facts." TRICK!

But then we can't build Ryan Mackey's scaled model without the facts.

psik

 

[psikeyhackr]

I thought I pointed out the principles I saw demonstrated. An elastic collision, coefficient of restitution, pressure and stiffness constant. All of which were grossly inaccurate for the purposes of demonstrating what happened.

.
It wasn't to demonstrate entirely what happened on 9/11.

Only to demonstrate that mass and distribution of mass had to affect what happened.

But since we don't have that information on the towers we can't figure out what happened.

psik

 

[psikeyhackr]

Fired from a pistol, the plane would outrun the bullet. The planes were traveling "fast as a 22" within the accuracy of your toy model.

500MPH is about 722ft/sec and a classic .22 round is only slightly supersonic when fired from a rifle. From a pistol, the plane wins.

You really haven't figured out the scale thing.

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Since I had no intention of doing that there was not any point.

psik

 

[FineWine]

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It wasn't to demonstrate entirely what happened on 9/11.

Only to demonstrate that mass and distribution of mass had to affect what happened.

But since we don't have that information on the towers we can't figure out what happened.

psik

As we know the locations of the external columns and the core columns, and we know the dimensions of the trusses, you might be arguing that knowing the exact placement of chairs, vending machines, and computers is vitally important. You never get around to telling us why. What about the "distribution" of mass in the towers is unknown? Are you playing a weird game with us? What sort of information do you claim not to have?

 

[GlennB]

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It wasn't to demonstrate entirely what happened on 9/11.

Only to demonstrate that mass and distribution of mass had to affect what happened.

But since we don't have that information on the towers we can't figure out what happened.

psik

I hope your NWO paycheck is huge this month, psikey. You're doing a fabulous disinfo job bringing the 9/11 CT cause into such disrepute.

 

[Furcifer]

An interesting problem, mostly book-keeping, and totally pointless in the long scheme of things.

That's all that useless ejuneerin stuff they learned you in school

Totally pointless unless you're buildin' one of these babies:

Tuned Mass Damper - Taipei 101

Slap one of these up in your apartment, add some acoustic tiles (non thermitic ones) and you could have some serious parties.

 

[Furcifer]

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Only to demonstrate that mass and distribution of mass had to affect what happened.

But since we don't have that information on the towers we can't figure out what happened.

If by "what happened" you mean what they did when they calculated the natural frequency of the building then yes, that's what you demonstrated.

We have that info, rw says it was 1/11 Hz, seems about right to me. Your model looks like it has a natural frquency of about 1 Hz. That's off by what, 1100%? Doesn't that mean your mass and stiffness must be considerably off the mark?

Just to clarify I said - "Your mass and stiffness is seriously not to scale"

 

[Minadin]

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Can you comprehend the difference between a DEMONSTRATION OF PRINCIPLE and a scale model?

The WTC was supposed to sway 3 feet at the top in a 150 mph wind. That was only 1.5% of its width. My model can sway a little more than 100% of its width at the top. If the model only swayed 1.5% it would be nearly impossible to see in the video. If a real skyscraper swayed that much it would probably collapse.

The airliner was only 1/2 of 1/10th of 1% the mass of the tower. I would have had to use something like a 22 bullet to have something small with a high velocity. It would damage the tower every time and I would hve to rebuild it for every variation.

The behavior of the tower changed with mass and its distibution which was the entire point. To show that that information about the towers is necessary for analyzing the 9/11 incidents. Which we do not have after 7.5 years.

psik

The difficulties involved in building a scaled-down physical model to study an event which must be necessarily destructive are exactly what I was talking about here:

http://www.internationalskeptics.com/forums/showthread.php?t=138860&page=2

in my discussion with thewholesoul. Unfortunately, he seems to have disappeared.

(maybe the NWO finally tracked him down)

You might be better off with a computer-based model, as it's easier to set up (no scaling needed) and a lot less work and time to adjust it for each iteration of your tests.

 

[Furcifer]

The difficulties involved in building a scaled-down physical model to study an event which must be necessarily destructive are exactly what I was talking about here:
http://www.internationalskeptics.com/forums/showthread.php?t=138860&page=2

Are you saying 1000 engineers working 8 hours a day for 7 years might come up with some good ideas? The nerve!

You might be better off with a computer-based model, as it's easier to set up (no scaling needed) and a lot less work and time to adjust it for each iteration of your tests.

psikey don't trust no cumpooter for his infermation. they can't be trusted fur nuttin. why ,theys a technougees learned folks youz whit dem billz a pay an a twoishun debits a plenty.

He's already reemptively dismissed any computer simulations as "untrustworthy". How he can say that totally boggles my mind, but it is on record.

 

[Newtons Bit]

Amazingly enough, if you get the deflection at various floors under a wind force (also available-I recall reading it, but cannot remember where), then model a cantelever with distributed load (wind load), you can, from the latter, get the distributed stiffness of the structure.
Incorporating the stifness into the model, you can then get the mass distribution from the eigen solution of the distributed stiffness model with distributed mass (take the natural frequency, which is known and in the NIST report (about 1/11 Hz IIRC) and converge on a solution)
It will be reasonably accurate...
An interesting problem, mostly book-keeping, and totally pointless in the long scheme of things.

Also one that involves ODE's. I don't think many truthers can solve those.