WTC Lightweight Steel Construction

The trade centers were detonated by Halliburton After the CIA Crashed remote control airforce cargo drones into them...thats official

reply to post by godfather420


I see that you confused ignorance and incredulity with math. Don't worry, its a common mistake among truthers. In fact, its often the primary argument.

Originally posted by -PLB-
reply to post by godfather420

 

I see that you confused ignorance and incredulity with math. Don't worry, its a common mistake among truthers. In fact, its often the primary argument.

I'm guessing this is your new answer to everything now you've ran out of arguments?

Where is your maths that shows how sagging trusses can put a pulling force on the columns?

reply to post by ANOK


Nah, its just the answer to a person who claims that the math "has been shown over and over again", and then fails to provide a link to it.

As for the sagging trusses, I see you are still confused by this simple concept. It has been explained to you in detail, but your state of denial is too strong. I even linked you to papers in which experimental data confirms the pull-in force. You are afraid to confront reality, which is that you are not capable of understanding simple concepts in physics. Since you don't listen to anything I say anyhow, I advice you to ask a fellow truther who has a bit more understanding of physics than yourself. Maybe you will listen to that person, although I suspect you fear this kind of confrontation and rather remain in denial.

reply to post by ANOK

It's not up to me to prove anything.

What a riot!

Calculations are not needed, how many times are you going to use this tactic when your arguments fail?

And it keeps getting funnier and funnier. Page after page of physics this and engineering that and then you come back with nonsense like "calculations are not needed". Then you wonder why after 10 years this stuff is going no where.

Proof is equal opposite reaction, and conservation of momentum laws.

No proof is math.

This has been explained to you a million times, but you just want to act ignorant and pretend the laws of motion don't count and demand calculations you know can't be done.

Sorry, but nothing's been explained except your complete inability to back up anything you are claiming.

You have to prove first of all that sagging trusses can put a pulling force on the columns.
Where are your 'calculations' for that?

You first.

Unless the phenomena can be demonstrated, the NIST report remains the hypothesis it is. Not fact, not theory, just a questionable hypothesis.

Its called gravity. Pretty much been proven. You should try and keep up with this stuff.

I mean you think PSF mean weight, so I have little faith in you understanding anything to do with engineering.

PSF can mean many things, like any other initialism, you have to know the context. Like with the rest of the language.

reply to post by ANOK


So ANOK, when any steel beam or truss is placed under a load, and then exposed to fire, what happens to said beam/truss?

I'll give you a few key words to help you in your quest:

Gravity, load, creep, plasticity, heat, time, temperature

Originally posted by -PLB-
As for the sagging trusses, I see you are still confused by this simple concept. It has been explained to you in detail, but your state of denial is too strong. I even linked you to papers in which experimental data confirms the pull-in force. You are afraid to confront reality, which is that you are not capable of understanding simple concepts in physics. Since you don't listen to anything I say anyhow, I advice you to ask a fellow truther who has a bit more understanding of physics than yourself. Maybe you will listen to that person, although I suspect you fear this kind of confrontation and rather remain in denial.

edit on 27-1-2012 by -PLB- because: (no reason given)

Your so called explanation of the sagging trusses is nonsense. I have explained to you many times why sagging trusses can not put a pulling force on the columns, and you have failed to address my points every time.

What papers?

Yes it is a simple concept, steel EXPANDS when heated up. If it was capable of pushing, or pulling, on the columns it would have done BEFORE it sagged. Why would it sag PLB if it could push out the columns?
The columns would resist the outward push of the expansion, causing the steel to bend downwards instead, but it would still be pushing against the columns due to it's expansion, it can not start pulling on the columns. If the truss can't push out columns it can not pull them in either, QED!

The truss is not putting any more force on the columns that it did before it sagged. Common sense PLB. No extra weight was added. If anything were to fail it would be where the truss joins the column, or are you now saying the bolts were stronger than the columns? How many time have you tried to say the bolts all failed because they were a weak point? So many contradictions in your story PLB. Let alone the insistence by Gen Radek that the trusses were 'light weight' and not as strong as beams, how do light weight trusses pull on massive box columns they are cross braced to other box columns? It's obvious none of you have taken a physics class and you accuse me of not understanding physics?

Let alone the fact that the fire was not hot enough or burned long enough to cause the failure.



Both towers BTW...



Hot enough to cause steel to sag, but not too hot for a Human?

And the same phenomena happened in both towers? Sorry but that is laughable.

BTW do you know how much pressure (PSF) a single floor assembly could withstand before failure? Do you have that information? If not then how do your calculations work?

Originally posted by GenRadek
reply to post by ANOK

 

So ANOK, when any steel beam or truss is placed under a load, and then exposed to fire, what happens to said beam/truss?

It depends? You do realise that the concrete and steel pans also took the load right? The trusses took the load of the whole floor assembly, concrete, steel pans, office contents etc. So unless the concrete and steel floor pans also sagged then the load would not cause the truss to sag.

I'll give you a few key words to help you in your quest:

Gravity, load, creep, plasticity, heat, time, temperature

And your point is? Time, less than one hour. Heat, not enough to cause steel to fail in less than one hour. So little heat people could stand in the very spot you claim the trusses sagged.

reply to post by ANOK


For example this paper (took me 10 seconds to find in Google. Google is a search engine in which you can type words and then it tries to find articles related to those words, try it sometime):

PERFORMANCE-BASED SIMPLIFIED MODEL FOR A STEEL BEAM AT LARGE DEFLECTION IN FIRE

But I don't expect you to understand a bit of it. Deny knowledge and understanding. (or what was that site motto again). But anyway, just try to grasp what happens after expansion. At least expansion is a concept you do understand. It is now time to take the next step.

Originally posted by ANOK

It depends? You do realise that the concrete and steel pans also took the load right? The trusses took the load of the whole floor assembly, concrete, steel pans, office contents etc. So unless the concrete and steel floor pans also sagged then the load would not cause the truss to sag.

But what was the concrete and steel pan? The trusses. The weight of the decking and concrete is what the loading was on the trusses. They werent solid pieces either ANOK. They were in segments as well. Also the steel is now more pliable due to the temp.

And your point is? Time, less than one hour. Heat, not enough to cause steel to fail in less than one hour. So little heat people could stand in the very spot you claim the trusses sagged.

Uh ANOK, trusses heat up VERY quickly when exposed to high temperatures. Dont you remember that? How long did it take for the large heavy trusses that supported the roof of McCormick Place in Chicago to fail in 1967? 27 minutes ANOK. 27 minutes for very large and heavy trusses to fail, from fire alone. What was burning? Just displays and typical stuff you'd find in a home, office, or what have you. The WTC's trusses were far smaller, and also some had been damaged or destroyed by the impacts, and they had crappy fireproofing. How is it ANOK, in your infinite wisdom, that large heavy steel trusses holding up a roof managed to collapse within a half hour, which only had to deal with winter snow loading, but the WTC floor trusses shouldnt have been able to fail in such amount of time? And dont give me this crap that "so little heat" was happening in that inferno. Fires like three things: fuel, air, heat. All three were in play, especially since there were huge holes in the side to allow fresh air to come in and fan the flames deeper into the building. You have a lot to learn about fire sciences ANOK. A lot.

Also, I forgot to ask, why do firefighters have a saying: Never trust a truss?

reply to post by -PLB-


Woah dude! They demonstrated sagging beams CAN cause a pulling force on the surrounding structure. Oops! Guess ANOK overlooked this fact.

Plus they tested a steel I-beam, and if it can do that, boy what will a steel truss do?

reply to post by thedman

Is a worthwhile read, thanks.

Here is the wiki for the article Writer:
en.wikipedia.org...

He was a professional man that helped the firefighting industry do its job.

He referred to the following TLC program aired in 2002:

In total, he brings a seasoned and expert opinion to the table. His job isn't to protect the building owners or engineers/designers, but to protect firefighters and people from fires and building collapse. The owners, opposingly, might have other motives due to their investments in the building or its design work. This is a point that many skip over. We need people who do not have anything to lose by being truthful.

NOTE: I find it interesting that Francis mentioned how winds can crack or dislodge fireproofing. I was just watching the TLC youtube clip I linked here and they mention that New York has wind problems.

reply to post by ANOK


So Anok, some time has past. You had enough time to read the paper I linked to, and follow my advice to use Google to find more information. Are you still confuse/in denial about sagging trusses exerting a pull in force? Or did you decide to drop the subject all together in an attempt to save face? You do realize that this is way too late and that beyond any doubt it is demonstrated that you are unable to grasp the most basic principles in physics? I can understand there is some sort of coping mechanism currently acting in your brain, either making you ignore the entire subject, or trying to find a way to weasel yourself out of this nasty situation. I am really curious about what it is gonna be.

Originally posted by -PLB-
PERFORMANCE-BASED SIMPLIFIED MODEL FOR A STEEL BEAM AT LARGE DEFLECTION IN FIRE

Oh dear, you need to read and understand that yourself mate. You obvioulsy looked at the pretty pictures, and made your conclusions without understanding the text that goes with it.

This is what I have already explained, from the PDF you linked...

In the initial stages of heating the restraint from the surrounding structure tends to resist the
expansion of a beam....

And thus it sags!

And...

However, the run-away deflection may be attenuated when the beam starts to behave as a heated cable hanging from the surrounding structure, provided that this is also capable of redistributing and supporting the heated beam at the applied load level during the fire, as shown in Figs. 4. However, the state of stress associated with a member under a combination of catenary action and thermal bowing is not unique for a given deflection. This depends on the temperature distribution in the member, its material properties and restraint
conditions.

First off, the WTC core columns and facade were more than capable of holding the load of the sagging trusses.
You have no evidence to the contrary. Secondly, we know the temperature distribution was not focused on the trusses, people were standing on the floors.

You also act like engineers don't take that into consideration when designing the floor assemblies. The information is known, and floors designed around those known facts. So they wouldn't build a floor assembly that could cause the columns to move in a fire due to sagging trusses. Do you think engineers are stupid?

Did you even read the conclusions?

Catenary action certainly occurs, and has been seen to affect a heated beam’s behaviour by
preventing run-away deflection at high temperature plus applied load. The tensile axial force
grows progressively as the deflection grows provided that some horizontal reaction stiffness
exists. A change of the horizontal restraint stiffness can have a large effect on the behaviour
of the beam at high deflection, and the loading on the beam can be carried very effectively as
catenary tension replaces bending...

The paper says nothing about the beam being able to pull in the columns. It's just a model 'used to predict the mid-span deflection and the tensile axial force of the heated steel beam at large deflection induced by the catenary action'.

Originally posted by ANOK
Oh dear, you need to read and understand that yourself mate. You obvioulsy looked at the pretty pictures, and made your conclusions without understanding the text that goes with it.

This is what I have already explained, from the PDF you linked...

In the initial stages of heating the restraint from the surrounding structure tends to resist the
expansion of a beam....

And thus it sags!

And? How is that contradicting the fact that sagging trusses can exert a pull-in force? Its not. Which part did I not understand? Or are you just making up nonsense in order to save your face? Lets look at the rest of your attempt to weasel yourself out of this.

First off, the WTC core columns and facade were more than capable of holding the load of the sagging trusses.
You have no evidence to the contrary. Secondly, we know the temperature distribution was not focused on the trusses, people were standing on the floors.

And what is your point here? Is this somehow supposed to change the fact that you were incapable of understanding the simple physics behind heated sagging trusses exerting an inward pull-in force?. You think that somehow, by instead of claiming it is impossible claiming that the force is not large enough, you are masking your epic demonstration of stupidity conscerning physics? Then you are wrong.

How about this, search the first post I made about this subject (it was in a thread with your friend bsbray or something), and look up what I think about NIST's theory of sagging trusses.

You also act like engineers don't take that into consideration when designing the floor assemblies. The information is known, and floors designed around those known facts. So they wouldn't build a floor assembly that could cause the columns to move in a fire due to sagging trusses. Do you think engineers are stupid?

Did you even read the conclusions?

No, I don't act like that. You don't have a clue about what I think about the sagging trusses theory. The whole point here is to confront you with the fact that you do not understand the simple physics behind the concept of sagging trusses exerting a pull-in force. You have been posting that this is impossible over and over. Now that you seem to realize how that was a massive blunder, you immediately start the standard disingenuous truther discussion tactic called shifting the goal posts. And right away you construct a straw man argument of "how I act". I nowhere act like you describe, you are are fat out lying.

The paper says nothing about the beam being able to pull in the columns. It's just a model 'used to predict the mid-span deflection and the tensile axial force of the heated steel beam at large deflection induced by the catenary action'.

Well done in shifting the goal post and constructing a straw man argument in an attempt to hide your miserable understanding in physics. Well, not well done at all, as it is all too obvious to any honest person.

Originally posted by -PLB-

Originally posted by ANOK
Oh dear, you need to read and understand that yourself mate. You obvioulsy looked at the pretty pictures, and made your conclusions without understanding the text that goes with it.

This is what I have already explained, from the PDF you linked...

In the initial stages of heating the restraint from the surrounding structure tends to resist the
expansion of a beam....

And thus it sags!

And? How is that contradicting the fact that sagging trusses can exert a pull-in force? Its not. Which part did I not understand? Or are you just making up nonsense in order to save your face? Lets look at the rest of your attempt to weasel yourself out of this.

And what is your point here? Is this somehow supposed to change the fact that you were incapable of understanding the simple physics behind heated sagging trusses exerting an inward pull-in force?. You think that somehow, by instead of claiming it is impossible claiming that the force is not large enough, you are masking your epic demonstration of stupidity conscerning physics? Then you are wrong.

How about this, search the first post I made about this subject (it was in a thread with your friend bsbray or something), and look up what I think about NIST's theory of sagging trusses.

So why haven't floor sections been tested in furnaces without fireproofing to see if this sagging can actually occur. The four tests that have been done so far with fireproofing did not fail.

It is so ridiculous that this is being debated without adequate data for TEN YEARS.

But then there is still the collapse problem.

A simple thought experiment which our engineering schools should have been able to simulate some time ago would be to merely remove five simulated levels from the north tower, 91, 92, 93, 94 and 95. That would leave a 60 foot gap with 15 stories floating in the air and 90 intact simulated stories below. Then let gravity take its usual immutably boring course. The bottom of the 15 stories would impact the top of the 90 in just under 2 seconds at 44 mph or 65 feet per second.

The 90 stories should be 1080 feet tall so if the 15 stories could maintain a constant 65 ft/sec while destroying them the collapse would take 16.6 second plus the 2 seconds totaling 18.6 seconds. But that is significantly longer then most estimates of collapse time therefore the 15 stories would have to accelerate while crushing stories heavier and stronger than themselves.

Now completely eliminating 5 stories to make that 2 seconds of acceleration possible is more damage than the airliner impact and fire could have done so we know that 60 feet of empty space never existed. But that thought experiment eliminates all argument about how hot the fires got because they could not instantaneously disappear five stories.

The levels had to get stronger and heavier going down and lighter and weaker going up. So how could 15 stories destroy all 90? Even assuming a 3 to 1 ratio of destruction, which I regard as unlikely, that would leave 45 stories standing which is not what happened on 9/11. So if that simulation is done and it comes nowhere near complete collapse then what is this nonsense that has been going on for more than TEN YEARS?

So why hasn’t any engineering school done such a simple simulation?

psik

reply to post by psikeyhackr

The levels had to get stronger and heavier going down and lighter and weaker going up. So how could 15 stories destroy all 90?

Because the debris mass increased with each floor it destroyed.
Most of the mass would contact the next lower floor. When it did the trusses would deflect downward and exert a pulling force on the exterior walls. Since the exterior columns had lost its connection with the higher floors, this pulling would force the columns unward.
Floor after floor would be chewed up bu the mass.

Originally posted by psikeyhackr
So why haven't floor sections been tested in furnaces without fireproofing to see if this sagging can actually occur. The four tests that have been done so far with fireproofing did not fail.

There have been tests, and sagging has been demonstrated. In order for the trusses to exert a pull-in force, they should not fail. Just like that you can't pull a horse with a broken rope.

It is so ridiculous that this is being debated without adequate data for TEN YEARS.

But then there is still the collapse problem.

A simple thought experiment which our engineering schools should have been able to simulate some time ago would be to merely remove five simulated levels from the north tower, 91, 92, 93, 94 and 95. That would leave a 60 foot gap with 15 stories floating in the air and 90 intact simulated stories below. Then let gravity take its usual immutably boring course. The bottom of the 15 stories would impact the top of the 90 in just under 2 seconds at 44 mph or 65 feet per second.

The 90 stories should be 1080 feet tall so if the 15 stories could maintain a constant 65 ft/sec while destroying them the collapse would take 16.6 second plus the 2 seconds totaling 18.6 seconds. But that is significantly longer then most estimates of collapse time therefore the 15 stories would have to accelerate while crushing stories heavier and stronger than themselves.

Now completely eliminating 5 stories to make that 2 seconds of acceleration possible is more damage than the airliner impact and fire could have done so we know that 60 feet of empty space never existed. But that thought experiment eliminates all argument about how hot the fires got because they could not instantaneously disappear five stories.

The levels had to get stronger and heavier going down and lighter and weaker going up. So how could 15 stories destroy all 90? Even assuming a 3 to 1 ratio of destruction, which I regard as unlikely, that would leave 45 stories standing which is not what happened on 9/11. So if that simulation is done and it comes nowhere near complete collapse then what is this nonsense that has been going on for more than TEN YEARS?

So why hasn’t any engineering school done such a simple simulation?

psik

It is even more ridiculous that you come with such a silly model.