Professional engineer Jon Cole cuts steel columns with thermate, debunks Nat Geo & unexpectedly repr

There are a few videos of WTC1's collapse that are not ambiguous this is one, look near top right to see the massive top section falling into the street,

www.youtube.com...

I'll look for others, BTW the above clip has a candid shot of WTC7 falling. It also clearly show the lean, but in this case, the lean only occurs near end of fall, so in the main straight down, unlike the towers. You will also see a flash during the collapse, I think that is a beacon of some other building in the background.

Go to the third screen at this link, (look for BBC demo wave) for a clear view of WTC1 upper part tumbling away. Also a lot more info from the other three screens,

www.911conspiracy.tv...

Originally posted by -PLB-
I exactly pointed out what you did wrong. You drew a horizontal component in the first image. There is no horizontal component (of any meaning) when the trusses are stiff. There is just gravity pulling them down. I just can't explain it any better.

So you're saying when the trusses are stiff, the perimeter columns don't experience any load from them at all?

If the perimeter columns aren't experiencing any horizontal load from holding that end up the truss up, then it wouldn't make any difference if they were connected at all, and the truss could just float in the air by itself.

You still have no idea what you're talking about.





Keep studying it and maybe you'll have a breakthrough.

Earlier you said you knew how to work free body diagrams and vectors. Obviously that was a lie.

Originally posted by Nutter
Those are the free-body, shear and moment diagrams you are having a problem explaining. Sorry bsbray11, PLB is correct about a horizontal force being added in this situation.

I was modeling a "pull" force, ie the force that hypothetically pulled the columns inward to cause the buckling. That force would necessarily have to be a horizontal tension force.

PLB was saying that as the angle of the truss changed, it would exert a greater tension force, since the truss wasn't getting any heavier as it got hotter. Either way according to NIST's theory there has to be some reason for the trusses to pull the the perimeter columns inward, or their theory is trash.

But what you are basically saying, and I do agree with you, is that NIST's theory is trash.

Originally posted by -PLB-
It seems to me that the columns were also heated and weakened. Whether the horizontal force as result of sagging was enough to make columns bow as much inward as was observed is a bit out of my league to determine, so can't comment on that.

You still haven't explained why the sagging trusses would be exerting a horizontal force to buckle the columns to begin with.

You've tried to say that both there was an additional mystery weight, as if the truss got heavier as it got hotter, and you've tried to say that the angle of the truss connection caused a greater horizontal force. You should now realize that both of those ideas are complete nonsense.

So what other reason can you think of for the trusses doing that?

Originally posted by -PLB-
I can't remember having a discussion with you. From what I read here it seems to me you agree that sagging of the trusses results in a horizontal component to the force on the perimeter columns? If so I am not sure what you are disagreeing to. If not, lets just disagree.

What? Did you read ANY of my posts?

I tried to explain to you why sagging trusses could not have horizontal force, and pull in the columns they were attached to. That was our conversation, remember?

I was not agreeing with you. It's no wonder you can't grasp these concepts we're trying to explain.

Its more because it came from a group of engineers that did all kind of experiments that made me take the theory serious. People who could actually back up what they say with experimental data. Besides, I only proposed it as a possible explanation, not the absolute truth.

No there are NO experimental data to back up your claims. I'm not interested in your personal possible explanations, only facts and science.

The trusses were deformed in the shape of a parabola. When you bent a piece of metal in the shape of a parabola the total width becomes shorter.

Oh dear again you fail to understand this concept. The reason the trusses sag is because they are malleable and stretching, not solid beams. They lose their ability to pull horizontally, that is why they sag in the first place.

The ENDS of the trusses will stay where they are, and the middle of the truss will sag more creating your 'parabola' (lol).

You can't be this dense, you have to be a troll.

I am explaining it to you, as you are the one who don't understand it. You are projecting your own shortcomings on me. As for me keeping the argument going, so far I am the only person who proposed an explanation at all for the observed bowing. Why don't you come with one?

No you're not explaining anything to me other than your obvious lack of physics knowledge. You have not explained the bowing at all. The bowing of outer columns was exaggerated by NIST. If anything it would have been caused by whatever was used to demolish the towers, it could not have been the floor trusses.

NIST failed to make trusses sag more than a couple of inches from fire tests, so they had to use a computer model to fake the amount of sagging their hypothesis required.

This BTW is what the floor trusses looked like...



And none of this explains how the core structure failed and completely collapsed. How NONE of the massive steel floor pans, or trusses, were found in the rubble. Or why most of the bodies were not discovered.

reply to post by smurfy


That leaning you see WTC 7 do is the outer walls falling on top of the debris pile. You don't see the other walls that are doing the same thing. This is classic implosion demolition.

That is why we can see the outer walls on top of the debris pile...



If it had actually leaned to the west, and continued to fall that way, then the east facing wall would be under the debris pile, along with the north and south walls.

Originally posted by bsbray11

Originally posted by -PLB-
I exactly pointed out what you did wrong. You drew a horizontal component in the first image. There is no horizontal component (of any meaning) when the trusses are stiff. There is just gravity pulling them down. I just can't explain it any better.

So you're saying when the trusses are stiff, the perimeter columns don't experience any load from them at all?

If the perimeter columns aren't experiencing any horizontal load from holding that end up the truss up, then it wouldn't make any difference if they were connected at all, and the truss could just float in the air by itself.

I thought I would clarify this with a diagram:




The trusses weren't actually sitting on top of the columns, in which case they'd be transferring their loads straight down. They were fasted onto the sides. The columns were still ultimately channeling the loads vertically but the way they were fastened would introduce horizontal forces too, but nothing that wasn't designed for.

If anything the trusses would fail where they're connected, long before they pulled in the massive columns they were attached to.

But really this is all rather pedestrian anyway, because we know there could not have been enough heat created in an hour to cause steel to become malleable.

Of interest is the maximum value which is fairly regularly found. This value turns out to be around 1200°C, although a typical post-flashover room fire will more commonly be 900~1000°C. The time-temperature curve for the standard fire endurance test, ASTM E 119 [13] goes up to 1260°C, but this is reached only in 8 hr. In actual fact, no jurisdiction demands fire endurance periods for over 4 hr, at which point the curve only reaches 1093°C.

www.doctorfire.com...

If the debunkers only understood how heat, thermal, transfer works they would know that room temps do not equate to steel temps. In an hour the steel would barely be warm, even if some did get hot it would not be anywhere near enough to cause unaffected steel to fail.

Absolutely love this video! I love how they try and prove that there's no way for therminte to burn through steel by trying to do it in the most rediculess way as possible! brilliant post, I cant believe our government is able to get away with crimes like this!

Originally posted by ANOK
reply to post by smurfy

 

That leaning you see WTC 7 do is the outer walls falling on top of the debris pile. You don't see the other walls that are doing the same thing. This is classic implosion demolition.

That is why we can see the outer walls on top of the debris pile...

If it had actually leaned to the west, and continued to fall that way, then the east facing wall would be under the debris pile, along with the north and south walls.

I understand that Anok,
The point I was making, was that it was a late event in the collapse, and that all below had disintegrated. The lean had no bearing on the collapse, other than acting like a shroud.

reply to post by ANOK


I don't really like your tone. I don't really care if you remain ignorant, so have a nice life.

reply to post by bsbray11


The horizontal force can be neglected when the trusses are stiff. When the trusses become flexible, the horizontal component increases. I hope you understand my point now. If not, I think we should just let it be.

reply to post by ANOK


"But really this is all rather pedestrian anyway, because we know there could not have been enough heat created in an hour to cause steel to become malleable."

Above quote from Anok's post.
That's something I didn't think of, it's not so much that you may be right, it's more that NIST did not do two allied things which I think are important, first is that I don't see mention of what you are saying, second is a time period for collapse and I see no mention of that either, one begets the other doesn't it? I see that as a fatal flaw in the report, no matter what the circumstances were. $10million up the Swanee!

reply to post by bsbray11


I starred your post because you are thinking correctly. But, I believe that those dampeners caused the connections to be zero moment. If so, there would only be shear left at the connections (vertical force), making the trusses into simple span beams. If not, then you would be correct.

But, then that initself becomes a conundrum. If the dampeners dampened the horizontal force or moment at the connections, how did plastically deformed trusses pull on the columns to begin with?

For the people who are interested, I found the article about the researchers who studied the effects which could be a possible explanation for the bowing. Maybe a structural engineer who did experiments can explain it better than me.

www.sciencedaily.com...

When you have a floor supporting weight, the floor starts sagging from the heat," Varma said. "It expands, but it's got nowhere to go so it starts bowing down, which produces pulling forces on the building's frame. It starts pulling on the columns and then it becomes longer and permanently deformed. After the fire, it starts cooling, and then it starts pulling on the columns even harder.

reply to post by -PLB-


Very interesting. I'd like to see his research. Especially what type of connections they are using. Star.

Originally posted by -PLB-
For the people who are interested, I found the article about the researchers who studied the effects which could be a possible explanation for the bowing. Maybe a structural engineer who did experiments can explain it better than me.

www.sciencedaily.com...

When you have a floor supporting weight, the floor starts sagging from the heat," Varma said. "It expands, but it's got nowhere to go so it starts bowing down, which produces pulling forces on the building's frame. It starts pulling on the columns and then it becomes longer and permanently deformed. After the fire, it starts cooling, and then it starts pulling on the columns even harder.

edit on 13-1-2011 by -PLB- because: (no reason given)

You know this is something thats always bothered me, when you heat steel it expands quite a lot. When I think about that in my mind that would push the columns out not pull them in.

Like this guy says once the steel cooled again it would then pull the columns in but the towers didnt get the chance to cool down.

I still cant figure out why heated steel can pull on the columns. Anyone ?

Originally posted by Nutter
reply to post by bsbray11

 

I starred your post because you are thinking correctly. But, I believe that those dampeners caused the connections to be zero moment. If so, there would only be shear left at the connections (vertical force), making the trusses into simple span beams. If not, then you would be correct.

But, then that initself becomes a conundrum. If the dampeners dampened the horizontal force or moment at the connections, how did plastically deformed trusses pull on the columns to begin with?

But steel also expands, even under load, that's why train rails buckle if there is nowhere to go, (you'll know that anyway). There is also the construction of the trusses which was of several different components, all acting differently if the heating and softening is true. Really, nothing makes sense, especially the bowing inward. If the collapse was an entirely "natural" event, it seems to me that there had to be an extraordinary loads at the point of collapse, as if a good part of the mass above the collision had already collapsed as far as the collision point, before a total collapse there is no real pointer to that. In the case of WTC1 the mast stood perfectly upright, and until total failure, but it did not go down straight either.

Originally posted by Nutter
I starred your post because you are thinking correctly. But, I believe that those dampeners caused the connections to be zero moment. If so, there would only be shear left at the connections (vertical force), making the trusses into simple span beams. If not, then you would be correct.

I tried to look up the role of the dampers while posting that above but I couldn't find what I was looking for. I know they absorbed some wind loads but I'm not sure what their role transferring loads from the trusses might have been. You could be right as far as I know.

But, then that initself becomes a conundrum. If the dampeners dampened the horizontal force or moment at the connections, how did plastically deformed trusses pull on the columns to begin with?

Exactly. That's what I was trying to find out, because it seems like they acted almost as the structural equivalent of a capacitor. If so then they would buffer any extra horizontal tension loads, if there were any to begin with, and I haven't seen any reason to suspect there were.

Imo the perimeter columns that were bucking, weren't because of the trusses, but because of the core structure being compromised. Just my opinion. When the WTC1 "collapse" initiated they just started folding over themselves where they were weakest at the exact same time the antenna start sinking straight down, and that antenna was supported by the core, not the perimeter structure, though the hat truss would try to redistribute all the core's loads onto the perimeter. Then it was a split second after that, that row after row of violent ejections started coming out until the "collapse" was completely obscured by the massive debris cloud.

Originally posted by -PLB-
The horizontal force can be neglected when the trusses are stiff. When the trusses become flexible, the horizontal component increases. I hope you understand my point now. If not, I think we should just let it be.

No, I need further clarification on why exactly you think this is the case. What is "flexible" in technical terms? Thermal expansion (? Severe integrity loss? Or what? And how do you think this is causing a significant horizontal tension force? Those 2 questions please.