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Originally posted by bsbray11
And this results in sagging in the middle when the two ends of the beam/truss are restrained.
And once again, for the steel to become like a big wet floppy noodle, it would have to reach temperatures that weren't shown or even suggested anywhere in the NIST report.
Originally posted by Joey Canoli
Originally posted by bsbray11
And this results in sagging in the middle when the two ends of the beam/truss are restrained.
It might. At what temp/expansion has your research shown that they should start sagging in the towers?
Originally posted by -PLB-
reply to post by bsbray11
Wow, let me get this straight: do you finally acknowledge there can be a inward pull force when the trusses are hot enough?
And your argument now has become that yes there can be a inward pull force but not at the temperatures in the WTC? If this is the case, it is interesting to see how far people will go with lying just to in an attempt to save their ego, acknowledging you are wrong to someone so "bad" as physics can be a pain. If this is not the case, why are you arguing that temperatures were not high enough?
Originally posted by bsbray11
Not hardly. I don't suppose you looked at the Cardington test I just linked to. There was not a single "pull force" anywhere to be seen. You are talking about borderline melting the steel, and a phenomenon that has never been observed in any study, ever. So you are talking about a mechanism that has no scientific validity to it, and that has nothing to do with the WTC.
Once again, I ask you to post whatever science you think there is to the WTC trusses becoming equivalent to catenaries. You've said more than once that such science exists but you must be confused as to what you're thinking of. Even NIST's own test debunked their hypothesis.
I am arguing that what you say happened at the WTC did not and could not have happened, on top of there being no evidence for it in the first place, and the mechanism does not make any sense. That has not changed. Look at the link I posted above. Those are expansion forces. Those are not wet noodle forces, and the truss does not act as a catenary. You are making all of that up, based on nothing.
NIST also did the experiment to physically show what would happen. Nothing happened, except some sagging.
So are you going to show me examples of beams or trusses pulling in columns because they're hot, or are you going to try to keep the petty bickering going? I can't even remember now how many times I've asked you to post the science you claim proves what you're saying. Apparently it contradicts the Cardington studies, whatever your mystery source is.edit on 1-4-2011 by bsbray11 because: (no reason given)
Originally posted by -PLB-
Ok I was already kind of surprised. I already pointed you to a list of links of publication in the very beginning we started to talk about this subject. You simply ignored that
Originally posted by -PLB-
You simply ignored that, and additionally you didn't do your own (re)search, you didn't do anything in fact. Just to see your response, take for example a look at this. Look at page 7, it shows actual experimental data.
Originally posted by -PLB-
The graph shows force not displacement.
Outward displacement is limited by the trusses as they can't keep on expanding, inward displacement is not limited as the trusses can, theoretically, continue to sag.
So, you finally acknowledge there can be a inward pull force? That would be a breakthrough.
It almost looks like it, but it seems you just can't directly do so as you think it makes you look like a fool.
Although your absurd position you keep clinching to that it is not possible at all makes you look way more like a fool in my opinion.
And yes, I took a quick look at those tests you posted. Is there any in particular point you want to make with it? Something like "look at test x, that proves y"?
Originally posted by bsbray11
The amount of displacement is obviously directly related to the force being applied. That's why I've been talking mainly about force, this whole time.
The expansion still represents a greater force at an even lower temperature, according to your own graph.
No, it would be a breakthrough if it made sense with the actual science you are posting. We already discussed way earlier in this thread that the trusses were not sitting directly on top of the columns and that for this reason they automatically represent a "pull force" on the perimeter columns from being attached to the sides, which they were designed for (thus the spandrel plates, dampers, etc.) and thus insignificant as far as trying to deflect the perimeter columns.
You are trying to show why there would be an additional "pull force" on these columns, no? The trusses are not going to become wet noodles until temperatures that there are no evidence for. The graph you just posted proved that greater forces are experienced by the expansion, at even lower temperatures, than by any sagging. And once again I ask you -- how many columns were buckled pushed outwards at the WTC?
If I were to acknowledge that there could have been a significant "pulling" force from sagging trusses, I would also have to acknowledge that there could have been trusses melted by the fire. Why don't I do this? Because there is no evidence of it, and it also doesn't make sense.
Let's talk about looking like a fool. Your own graph that you just posted shows that the expansion forces are greater than when the truss is heated to 850 C. There is no evidence that trusses were heated to 850 C, especially since that's about what the temperatures of the fires themselves would have been at most, barring a brief flashover. There is no evidence that columns were even buckling outwards from the greater force at the slightly lower temperature, which they should have been according to your graph. And you say I'm being stubborn because I don't want to look like a fool?
And you are saying it's impossible for the columns to be pushed outwards by an even greater force, at an even lower temperature?
Or you could just read the conclusion of the study they released based on their tests. I'll post it for you if you want.
Originally posted by -PLB-
And this is obviously wrong. Yet another physical concept you are unable to grasp, sigh. Outward bowing is limited by the amount of expansions of the trusses. Inward bowing is not limited by anything.
The expansion still represents a greater force at an even lower temperature, according to your own graph.
Yes. Point being?
And I already pointed out that eccentric loading results in an angular force, not a pull force.
So you acknowledge the mechanism is possible?
This makes no sense. 750 degrees != 1500 degrees. 750 degrees isn't that odd for office fires.
You are being a fool because you have been denying there could be a horizontal pull force at all.
And you are saying it's impossible for the columns to be pushed outwards by an even greater force, at an even lower temperature?
Nope, keep you delusion in check, you are imagining thing I never said again.
Sure, I wouldn't want you to have double standards, mister I don't want to follow your links and you should spell it all out for me.
Structural damage caused by the fire included distortion of a number of trusses and universal beams and axial shortening of five columns by 100mm. The deflection of the trusses produced dishing of the floor of up to 600mm relative to the columns. The concrete floor slab separated from its metal decking in some areas but generally followed the level of its deflected supporting members. Despite large deflections, the structure behaved well and there was no collapse of any of the columns, beams or floors. [115]
The behaviour of the structure and the floor members showed that a steel frame designed to BS 5950 Part 8 is structurally safe when exposed to a severe fire. The study [115] carried out after the Broadgate fire showed that when fire affects only part of a structure (compartmentation) and when the framework acts as a total entity structural stability is improved.
Originally posted by -PLB-
You are being a fool because you have been denying there could be a horizontal pull force at all. I can't tell if this force was actually there, and if it was there if it was strong enough. I just pointed out that it could have been the cause for the observed bowing of the columns. And a good one at it.
Originally posted by bsbray11
Yes, it's actually limited by temperature there Einstein. Temperatures that you don't have.
Well let's see. The expansion force is larger than any "pull" force, and occurs at even lower temperatures, and yet you don't see any columns bowing outward at the WTC. I'm not going to spell it out for you. If you're as smart as you pretend to be, you wouldn't need it spelled out.
Something else happens at those temperatures: steel begins glowing red, increasingly orange, in broad daylight, and is easy to see.
An angular force has a horizontal component. Once again we go back to you not understanding vector math or free body diagrams.
Exactly. It isn't odd for fire. Let me guess, you think the steel is going to be the exact same temperature as the fire. No surprises there. Maybe you would do good to look up what "entropy" means, or learn a little bit about convection or thermodynamics in general.
And yet I am telling you that the truss setup would have naturally produced a horizontal force on its own? I am telling you that the force you are describing is negligible, and the mechanism you are describing for failure is completely unfounded.
Then where is the outward bowing?
It should have been more widespread and more visible than inward bowing, because (a) the force for it is greater, and (b) it happens at even lower temperatures.
Structural damage caused by the fire included distortion of a number of trusses and universal beams and axial shortening of five columns by 100mm. The deflection of the trusses produced dishing of the floor of up to 600mm relative to the columns. The concrete floor slab separated from its metal decking in some areas but generally followed the level of its deflected supporting members. Despite large deflections, the structure behaved well and there was no collapse of any of the columns, beams or floors. [115]
The behaviour of the structure and the floor members showed that a steel frame designed to BS 5950 Part 8 is structurally safe when exposed to a severe fire. The study [115] carried out after the Broadgate fire showed that when fire affects only part of a structure (compartmentation) and when the framework acts as a total entity structural stability is improved.
And it goes on.
guardian.150m.com...
Originally posted by -PLB-
reply to post by ANOK
Your alternative explanation is noted. I have to congratulate you for finally actually come with one.
Originally posted by -PLB-
Originally posted by bsbray11
Yes, it's actually limited by temperature there Einstein. Temperatures that you don't have.
But luckily you placed temperature sensors in the buildings that exactly measured the temperature of the trusses. Now I only need to wait until you publish that data.
Well let's see. The expansion force is larger than any "pull" force, and occurs at even lower temperatures, and yet you don't see any columns bowing outward at the WTC. I'm not going to spell it out for you. If you're as smart as you pretend to be, you wouldn't need it spelled out.
Come on spell it out. Make me laugh.
Something else happens at those temperatures: steel begins glowing red, increasingly orange, in broad daylight, and is easy to see.
At 750 degrees its not that bright.
Anyway, Cole is actually arguing that the columns were glowing. Do you disagree with Cole?
An angular force has a horizontal component. Once again we go back to you not understanding vector math or free body diagrams.
So any horizontal component is now a pull force. Sure, whatever you want.
Exactly. It isn't odd for fire. Let me guess, you think the steel is going to be the exact same temperature as the fire. No surprises there. Maybe you would do good to look up what "entropy" means, or learn a little bit about convection or thermodynamics in general.
Bottom line is that I do not know what temperatures the trusses reached. Unlike you who seem to have some secret data you are about to publish. Go make a convincing argument.
And yet I am telling you that the truss setup would have naturally produced a horizontal force on its own? I am telling you that the force you are describing is negligible, and the mechanism you are describing for failure is completely unfounded.
No, you were claiming that this force wasn't possible at all. Keep the lie going.
Then where is the outward bowing?
Pfffff, once again, outward bowing is limited by the amount of expansion of the trusses and can be completely unobservable when the trusses start to sag soon enough. But maybe it was observable, I don't know.
It should have been more widespread and more visible than inward bowing, because (a) the force for it is greater, and (b) it happens at even lower temperatures.
No it should not. Force != displacement. Is that really so hard to grasp?
Structural damage caused by the fire included distortion of a number of trusses and universal beams and axial shortening of five columns by 100mm. The deflection of the trusses produced dishing of the floor of up to 600mm relative to the columns. The concrete floor slab separated from its metal decking in some areas but generally followed the level of its deflected supporting members. Despite large deflections, the structure behaved well and there was no collapse of any of the columns, beams or floors. [115]
The behaviour of the structure and the floor members showed that a steel frame designed to BS 5950 Part 8 is structurally safe when exposed to a severe fire. The study [115] carried out after the Broadgate fire showed that when fire affects only part of a structure (compartmentation) and when the framework acts as a total entity structural stability is improved.
And it goes on.
guardian.150m.com...
Ok, now try to make a coherent point. Or do you want me to guess?
The behaviour of the structure and the floor members showed that a steel frame designed to BS 5950 Part 8 is structurally safe when exposed to a severe fire. The study [115] carried out after the Broadgate fire showed that when fire affects only part of a structure (compartmentation) and when the framework acts as a total entity structural stability is improved.
Originally posted by -PLB-
reply to post by ANOK
Your alternative explanation is noted.
I have to congratulate you for finally actually come with one. But your manners are still of such a shameful degree that I don't really care to have a conversation with you.
Originally posted by ANOK
LOL you're taking notes huh, how is that working for you? When will you be honest and actually look at the evidence and the logical explanation for that evidence without being influenced and biased by someone elses claims? This just shows me you are not knowledgeable enough to think this through yourself, or you are
outright lying about everything you claim. We know you lie, you've already proved that 'Mr. Electrical Engineer'.
LOL my manners? From someone who started this discussion with outright lies as to who they are? Why should I be polite with you? You should think yourself lucky anyone is even bothering to respond to you.
Are you actually going to continue to discus your claims, or is this just your cop out because you have nothing left?
Where is the evidence that the bowing was not the aluminum cladding? You are supporting a claim you can not even supply evidence for. You know this.