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The NIST report, start to finish

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posted on Apr, 24 2011 @ 12:53 PM
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Originally posted by psikeyhackr
So somehow they got from 14 inches in two hours with double the expected load to 45 inches in less than ONE HOUR because that is the time the south tower came down in

We've already been through some of this, the trusses they tested were fireproofed, and were about half as long as the trusses we're now discussing. They also were undamaged, rather than having a plane crash into them. What do you think will happen if you disconnect whole floor regions as can be seen in the figures NIcon referred to?


and how do they explain the 22 degree tilt in the broken top of the south tower?

I'm not sure what you are looking for here, the failures occurred in the east wall and progressed from there.




posted on Apr, 24 2011 @ 02:11 PM
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Originally posted by psikeyhackr
I think some people have decided that they want to believe crap that is REALLY, REALLY DUMB.


I've been staying out of this thread, since exponent is far more knowledgeable than I am, but for Christ's sake STFU when you start to say stuff like this!

Your ridiculous name-calling and overall childishness and immaturity needs to stop! GROW THE **** UP!



posted on Apr, 24 2011 @ 06:22 PM
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Originally posted by Varemia

Originally posted by psikeyhackr
I think some people have decided that they want to believe crap that is REALLY, REALLY DUMB.


I've been staying out of this thread, since exponent is far more knowledgeable than I am, but for Christ's sake STFU when you start to say stuff like this!

Your ridiculous name-calling and overall childishness and immaturity needs to stop! GROW THE **** UP!


What is more ridiculous than the nation that put men on the Moon not being able to have Official Government Sources provide the distributions of steel and concrete on buildings designed before 1969? Doesn't that have to be figured out for skyscrapers?

The NIST report can't even specify the total amount of concrete even though it was in brochures given to tourists. Why hasn't the break and tilt of the top of the south tower attracted the interest of physicists at engineering schools all over the country? Physicists don't believe in CURIOSITY? Oh yeah, that doens't have anything to do with science.

Childish comes nowhere near accounting for the absurdity of 9/11. The fact that the majority of high school kids weren't saying airliners could not do that in 2002 is merely proof of the incompetence of the educational system.

So where is a self supporting physical model that can be completely collapsed by the fall of its top 15%? If it could happed to the north tower shouldn't a physicist be able to build it?

psik



posted on Apr, 24 2011 @ 08:37 PM
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reply to post by exponent
 


My calculations give an approximate end point angular deflection of 11.6 degrees for a long span truss with a 45 inch mid span deflection. If the max deflection occurred on the external side of mid span then this value would be slightly higher.

I was then going to do some calculations based on the principle outlined bellow:


Originally posted by exponent

Originally posted by ANOK
I want to know why you and PLB, and probably others, think that sagging trusses put more force on the columns than non sagging trusses?

Where is your physics explanation for that?

They don't put more force on the columns, they exert a force in a different direction. As they sag, they become somewhat like a chain hanging between the core and the outer wall. Chains exert a significant portion of their weight horizontally inward, due to the geometry of their hanging: en.wikipedia.org...


When it dawned on me (d'oh for not picking it up earlier) that that mechanism for horizontally inward force application does not apply in this case. If it did, smaller deflections would result in larger inward forces and larger deflections would result in smaller inward forces. The reason for this is, unlike a rope or chain, tensile forces applied at the supports are not responsible for the amount of curvature in the member and are negligible compared with the member's own internal forces for keeping it straight (in the same way the end moments in this simply supported configuration are negligible for keeping it straight and in design are assumed to be zero).


edit on 24-4-2011 by Azp420 because: (no reason given)



posted on Apr, 24 2011 @ 08:54 PM
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reply to post by psikeyhackr
 


All I'm asking is that you debate with a tone of civility and respect. You sound like a crazy hobo with your incessant ranting, no offense intended.



posted on Apr, 24 2011 @ 10:09 PM
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reply to post by Varemia
 


A crazy hobo
hey man, even hobos know Newtons 3rd law...if I drop my bottle it will break...



posted on Apr, 24 2011 @ 10:15 PM
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Originally posted by Varemia
All I'm asking is that you debate with a tone of civility and respect. You sound like a crazy hobo with your incessant ranting, no offense intended.


Okay so,

1st, you ask for "civility and respect."

2nd, you proceed to tell him he sounds "like a crazy hobo with (his) incessant ranting."

And finally, to excuse everything you just posted, you top it off with "no offense intended." Of course you can say anything, and it's okay as long as you add "no offense intended." It's a classic finish to offensive statements.



Anyway if you are going to cop out of responding to what someone else posts, there are better ways to do it, without making yourself out to be a hypocrite in the process.



posted on Apr, 24 2011 @ 10:20 PM
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reply to post by psikeyhackr
 



In the 60's they did not have computers but they did have scale models and wind tunnel testing which is still done today. Back then, you did not boot up you Sun workstation and get going. You did the math with the information you are provided.

I know that I have read that there was 425,000 cubic yards of concrete used to construct the WTC. Is that the figure you found and why do you feel it is so prevelant? Even if you had the amount of concrete you do not have the contents of the building, nor do most people add the weight of the people in the buildings at the time of impact and time of collapse. Every piece of mass would matter when you attempt to create an equation to show how it collapsed.



posted on Apr, 24 2011 @ 10:21 PM
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Originally posted by esdad71
reply to post by Varemia
 


A crazy hobo
hey man, even hobos know Newtons 3rd law...if I drop my bottle it will break...


Tell that to Bazant.

norcaltruth.org...

After NINE YEARS I can't have much respect for people that have not resolved grade school physics. Notice that no one has pointed out where the NIST specified the total amount of concrete in the towers.

Have I called people names at any time?

Let's see you build a self supporting model that can completely collapse. I could RESPECT that. It would involve REAL PHYSICS.

psik



posted on Apr, 24 2011 @ 10:48 PM
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reply to post by psikeyhackr
 


Can I ask a simple question? Why would NIST require the amount of concrete used and how do we know they did not use it at anytime. Is that stated somewhere?



posted on Apr, 24 2011 @ 10:48 PM
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Originally posted by esdad71
reply to post by psikeyhackr
 
In the 60's they did not have computers but they did have scale models and wind tunnel testing which is still done today. Back then, you did not boot up you Sun workstation and get going. You did the math with the information you are provided.


In the 60's they did not have computers

In the 60's they did not have computers

In the 60's they did not have computers

In the 60's they did not have computers

In the 60's they did not have computers

Why do I need to call people names when they write stuff like that? I am supposed to RESPECT people that write stuff like that?

Ever heard of the ENIAC? It began operation in 1945.

library.thinkquest.org...

Ever heard of the UNIVAC that predicted the Eisenhower election in 1952?

www.wired.com...

In the 60's they did not have computers

In the 60's they did not have computers

In the 60's they did not have computers

JEEZUS H. CHRIST!!!

Now see I didn't do any name calling so I must have shown proper respect.

ROFLMAO

psik



posted on Apr, 24 2011 @ 10:54 PM
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Originally posted by esdad71
reply to post by psikeyhackr
 


Can I ask a simple question? Why would NIST require the amount of concrete used and how do we know they did not use it at anytime. Is that stated somewhere?


I didn't say they didn't use it I said they didn't put it in their report. If they didn't put it in their report I have know way of knowing if they did have it and did use it.

But if they had it and used it

Then why didn't they put it in their report? And yet they put the total for the steel in three places. They even admit in 3 locations that they needed the distribution of weight information to analyze the impact of the south tower. BUT THEN THEY DIDN'T DO IT. But they provided a GREAT graph of the oscillation of the building from the impact. That is why we can compute that the building deflected 15 inches.

Wouldn't the mass of the concrete affect that deflection due to the conservation of momentum?

psik



posted on Apr, 24 2011 @ 10:56 PM
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reply to post by psikeyhackr
 


We are talking about software to recreate or design models, not computers. Are you serious in thinking that I thought there were no computers in the 60's? I do not need any links for reference but thank you.

We are talking about software to recreate or design models, not computers. Are you serious in thinking that I thought there were no computers in the 60's? I do not need any links for reference but thank you.

We are talking about software to recreate or design models, not computers. Are you serious in thinking that I thought there were no computers in the 60's? I do not need any links for reference but thank you.

We are talking about software to recreate or design models, not computers. Are you serious in thinking that I thought there were no computers in the 60's? I do not need any links for reference but thank you.

We are talking about software to recreate or design models, not computers. Are you serious in thinking that I thought there were no computers in the 60's? I do not need any links for reference but thank you.

uh oh, I think my computer broke like yours.


I was simply referring to the introduction of CAD to the mainstream? The everyday person did not have access to 3D modeling of just about any type during the planning of the WTC. They may have used computers for complex calculations but there was no good UI for use.



posted on Apr, 24 2011 @ 11:00 PM
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Originally posted by esdad71
reply to post by psikeyhackr
 

We are talking about software to recreate or design models, not computers. Are you serious in thinking that I thought there were no computers in the 60's? I do not need any links for reference but thank you.


YOU SAID IT!

I apologize for my inability to read a mind as BRILLIANT as yours.

psik



posted on Apr, 24 2011 @ 11:21 PM
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Originally posted by Azp420
When it dawned on me (d'oh for not picking it up earlier) that that mechanism for horizontally inward force application does not apply in this case. If it did, smaller deflections would result in larger inward forces and larger deflections would result in smaller inward forces. The reason for this is, unlike a rope or chain, tensile forces applied at the supports are not responsible for the amount of curvature in the member and are negligible compared with the member's own internal forces for keeping it straight (in the same way the end moments in this simply supported configuration are negligible for keeping it straight and in design are assumed to be zero).


The problem with this line of thinking is that we're not dealing with a normal in-service intact truss with upper and bottom members balanced. We're dealing with rather significant deflection and the breaking or deforming of internal truss elements. It's certainly true it doesn't become exactly like a catenary, but the forces are exerted in a similar fashion.

If the truss was deformed, then cooled in-situ and then was loaded in a way to ensure no moment action formed by the geometry then we could assume it was a simple element, but none of these things are true.



posted on Apr, 25 2011 @ 12:42 AM
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My calculations indicate that a 45 inch sag should cause a 60 foot truss to tilt down 7 degrees at the ends.

That should pull the columns in less than 8 inches. Doesn't sound like a big deal to me.

psik



posted on Apr, 25 2011 @ 12:51 AM
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reply to post by exponent
 



We're dealing with rather significant deflection


If it has indeed become like a catenary then larger deflections result in smaller inwards forces. At which point is this catenary action supposed to take over?


and the breaking or deforming of internal truss elements.


Even with failed truss elements the resulting bending capacity of the truss is still what is holding it at an 11.6 degree angle of deformation (at the end point). For catenary action to be playing any significant role in holding the truss at an 11.6 degree angle the resulting tensile stresses in the truss would far exceed the capacity of the steel.

11.6 degrees is still a very small angle with regards to catenary action.

reply to post by psikeyhackr
 



My calculations indicate that a 45 inch sag should cause a 60 foot truss to tilt down 7 degrees at the ends.


You have to take into account the curvature of the truss. 7 degrees would be the average angle for one half of the truss but the angle at an end would be slightly higher than this.


There are some good formulas here.


edit on 25-4-2011 by Azp420 because: (no reason given)



posted on Apr, 25 2011 @ 01:19 AM
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Originally posted by exponent

Originally posted by bsbray11
I said NIST did not prove why the Twin Towers "collapsed." How do any of the things you listed contradict this? They don't.

The idea is to provide a solid foundation to discuss the more contentious issues. I've said this a few times in this thread now and I don't understand why you don't get it.


And I am telling you now that no one here was ever in disagreement with the fact that fire heats steel.

So you are wasting everyone's time by breaking your "argument" down into points that were never contested in the first place. If you are ready to move on from "fire heats steel" and "steel without fireproofing heats up faster," then please, continue. And?


If we start arguing about the collapse right now, you could argue that 'trusses cant pull in', and we would have to go to that discussion and resolve that before discussing the collapse any further.


Nothing you have posted so far even begins to justify the separate claim that trusses will pull perimeter columns inward when they get so hot.



No one is going to argue with you that fire will heat up steel.

Guess you haven't read this thread.


I have not read every post in this thread but I would be very surprised if you could find me a quote of someone claiming that fire can not heat steel.



Why do you think NIST ignored all the eyewitness testimony, among other evidence? I notice you ignored that too.

They didn't. They conducted a number of in-person interviews. An awful lot of details from them are contained in NCSTAR 1-7 and 1-8.


Okay, and they specifically consider the relevance of numerous testimonies of explosions on what page of either PDF?

wtc.nist.gov...

1-7: wtc.nist.gov...

1-8: wtc.nist.gov...


I just did a search through both of those documents and the only references to explosions were...

1-7: (1) The 1993 bombing, (2) explosions in relation to the impacts and "collapses" only. The cause of an "explosion" in relation to the impacts is obvious. The relationship of "explosions" to the "collapse sequence" is not considered in any detail whatsoever. And of course, no mention at all of the numerous explosions reported in parts of the building and at times that cause them to be anomalous, such as various basement-level explosions during impact and other witness testimonies.

1-8: A references to a basement-level explosion coinciding with a plane impact is referenced on page 90. However this testimony is simply provided as stated by the witnesses and no attempt is made whatsoever to investigate or analyze what may have actually caused it. Then more references to the 1993 bombing. And again, scores of other testimonies of explosions are neglected to even be mentioned at all.


So let me clarify that I am asking you where NIST actually investigated these explosions that I can provide many sources for, let alone where they were able to form any conclusion about them.



posted on Apr, 25 2011 @ 07:10 AM
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Originally posted by Azp420
If it has indeed become like a catenary then larger deflections result in smaller inwards forces. At which point is this catenary action supposed to take over?
...
Even with failed truss elements the resulting bending capacity of the truss is still what is holding it at an 11.6 degree angle of deformation (at the end point). For catenary action to be playing any significant role in holding the truss at an 11.6 degree angle the resulting tensile stresses in the truss would far exceed the capacity of the steel.


Rather than try and convince you on my own, I'll just provide a third party source. here is an FEA analysis by an independent group from the UK.



As you can see, they come to a similar conclusion to NIST. Trusses being supported at a deformed angle will exert pull-in forces. I'm not sure why you are debating this as there is really no other choice once truss elements have been sufficiently damaged. How else would you explain their behaviour?
edit on 25/4/11 by exponent because: (no reason given)



posted on Apr, 25 2011 @ 07:14 AM
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Originally posted by psikeyhackr
My calculations indicate that a 45 inch sag should cause a 60 foot truss to tilt down 7 degrees at the ends.

That should pull the columns in less than 8 inches. Doesn't sound like a big deal to me.

Please show your working.


Originally posted by bsbray11
So you are wasting everyone's time by breaking your "argument" down into points that were never contested in the first place. If you are ready to move on from "fire heats steel" and "steel without fireproofing heats up faster," then please, continue. And?
...
I have not read every post in this thread but I would be very surprised if you could find me a quote of someone claiming that fire can not heat steel.

What a surprise, you start commenting about something before you've even read an 8 page thread. This is becoming a common feature with you now isn't it!


Nothing you have posted so far even begins to justify the separate claim that trusses will pull perimeter columns inward when they get so hot.

Please see above for an independent analysis which confirms the same effects.


Okay, and they specifically consider the relevance of numerous testimonies of explosions on what page of either PDF?
...
So let me clarify that I am asking you where NIST actually investigated these explosions that I can provide many sources for, let alone where they were able to form any conclusion about them.

Discussion of explosions occurs in many parts of the NIST report. If you can actually provide the sources or specify an explosion I can do some searching. If you can't be specific then there's no real way for me to search accurately.



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