The Twin Towers at free fall speed

[deep]

Jay Howard: To help me put your concerns into perspective, can you provide a bit of background on your education and experience in this field?

Why does it matter one way or the other? He's not asking you to accept his professional opinion.

 

[Dave_46]

Newton's Bit, Ryan, Architect, or anyone else: Is the above not a description of what the Cardington tests were?

<snip>

The structure in the Cardington tests was different from the WTC towers. It was built to represent the type of structure being erected in the 1990's, so would not be representative of the WTC towers

Also, a major difference, it wasn't compromised by having an airliner flown into it.

Dave

(I was present for a couple of the tests, but only as a rubbernecker, i wasn't involved)

 

[twinstead]

Why does it matter one way or the other? He's not asking you to accept his professional opinion.

It would help this layman, however, to know if it was indeed a professional opinion or just some guy who probably has no idea what he's talking about with an opinion.

 

[dafydd]

It would help this layman, however, to know if it was indeed a professional opinion or just some guy who probably has no idea what he's talking about with an opinion.

I second that.

 

[W.D.Clinger]

It would help this layman, however, to know if it was indeed a professional opinion or just some guy who probably has no idea what he's talking about with an opinion.

Judging by his first post, in a thread remarkably similar to what this one has become, I'm guessing he learned his craft from Alan Sokal:
http://www.internationalskeptics.com/forums/showthread.php?t=88816

If you can figure out what "danda corroboration" means, or who "S. Pepper" is/was, please let us know.

Continuing in that thread, don't miss posts #12, #22, #25, #26, #35, #43, and of course #51. After reading #56, I gave up on Jay Howard. Post #111 expounds an excellent summary of my current opinion.

For additional opinions and déjà vu, I recommend a Google search on "Jay Howard"+"horse pucky" or "Jay Howard"+"stundie".

ETA: From http://www.physforum.com/index.php?showtopic=19501&st=735

I used to work in a bronze foundry, so although I'm no expert and bronze is not steel, I'm not unaware of the factors involved in heating metal, how impurities affect the pour, timing, temps, etc.

 

[daws59]

How do you scale gravity?

with a very strong rope?

 

[alexi_drago]

with a very strong rope?

A big elevator.

 

[jaydeehess]

Well, I'm still looking, but I've have been unable to find an FEA that includes the corrogated steel underbelly of the concrete slabs. This might just be an oversight on my part, but if not, it would be significant to the behaviour of the concrete--especially in terms of the accumulation and dissipation of heat.

The steel pan was there to allow the pouring of the concrete during construction. AFAIK it was never intended to be a load carrying structural component and would have done little to change the behaviour of the concrete to the heat.

Also, one of the criteria in NCSTAR 1-5B states "Section thicknesses were sized so that 600 C temperatures could be obtained with a fire release rate (Q) of 2 MW to 3 MW in less than an hour" (115)

Section 9.2, what else does it say? There are three more criteria plus the size of the compartment used in the test approximated the size of a typical WTC compartment.

Call me skeptical, but a criterion like that simply begs the question of the rate of heat accumulation of steel members.

Not at all. IF the FDS/FSI correctly predeicts the rise of temp of the steel tested then it may be assumed that it will also do so for larger, more expensive pieces of steel.

This ain't rocket science, this is basic test design. Now, does that mean that everything NIST did was tainted with design flaws? No, of course not. It just means this particular test is not designed to see how hot various steel members would get under the test conditions.

Correct! It was designed to see if the simulation correctly predicts the temperature of the steel components tested which were selected by criteria that would approximate the size and shape of the components in the towers but which were less thick. Conduction through a varying thickness is hardly something that needs more testing, its a well established science is it not. However testing a full thickness component just for the sake of doing so will also drive costs up.

Invariably, someone here will respond that this particular test isn't supposed to test for thermal response of the steel, even though the objective of the chapter claims:

"The time varying temperatures of the steel components were measured to determine the thermal response of structural steel components to controlled room fire conditions, including flame immersion and to establish a data set to validate predictions of the temperature rise of insulated and uninsulated structural steel components." (115)

Yes, and the predictions for these tested components matched the physical tests
THUS THE FDS/FSI are validated!!!!!!!!!!!

Same goes for the oft cited bugaboo of the TM..."NIST only found columns that reached 250 C on the fire floors". That is a mischaracterization. NIST could positively identify some columns from fire floors that were not dug up out of the underground rubble fire zone and those columns showed they had reached 250 C AND the sims also predict that these very columns would have been at temps in that range THUS validating the sim predictions in general.

 

[jay howard]

It would help this layman, however, to know if it was indeed a professional opinion or just some guy who probably has no idea what he's talking about with an opinion.

If you can't distinguish a professional opinon from a lay opinion, then what difference does it make?

 

[twinstead]

If you can't distinguish a professional opinon from a lay opinion, then what difference does it make?

Uh, a professional opinion is offered by a professional, a lay opinion is not. What is there to distinguish?

 

[carlitos]

Ah, it must be the metatheory. Thanks for playing.

 

[DavidJames]

If you can't distinguish a professional opinon from a lay opinion, then what difference does it make?

Does that mean you don't want to share any education and industry qualifications you might possess?

Just say so and I'm pretty sure the subject will go away.

 

[jay howard]

The steel pan was there to allow the pouring of the concrete during construction. AFAIK it was never intended to be a load carrying structural component and would have done little to change the behaviour of the concrete to the heat.

And you know this how? Did you intuit this?

Section 9.2, what else does it say? There are three more criteria plus the size of the compartment used in the test approximated the size of a typical WTC compartment.



Not at all. IF the FDS/FSI correctly predeicts the rise of temp of the steel tested then it may be assumed that it will also do so for larger, more expensive pieces of steel.

So you think the decision to use steel thicknesses that "were sized so that 600 C temperatures could be obtained with a fire release rate (Q) of 2 MW to 3 MW in less than an hour" was a way to keep costs down? Really?

There is a perfectly reasonable explanation of this test, but the fact is it is not a test of how hot steel gets under certain temps for a known amount of time.

This is the issue here: we know a few things for certain about the tower collapses:

1. How long the fires burned
2. How hot office materials, jet fuel and other hydrocarbon surrogates burn
3. The chemical make up and geometric config of steel members of WTC

So, if my theory is that fire heated the steel and weakened it, that is a very testable theory given all we already know. By extension, if you take the floor trusses and heat them hotter and for longer than the fires burned, and load them to their maximum capacity, and they do NOT exhibit the same degree of deformation as the simulations, what can you conclude from that?

That the tests must be leaving something out?

or

That the simulations do not correspond to the conditions they purport to represent?

or

Both?

I'm not trying to be tricky or snarky here. This is pretty straight forward.


.

 

[Justin39640]

3. The chemical make up and geometric config of steel members of WTC

Don't forget that they also simulated the giant hole in the building left by the giant airplane that hit it.

 

[Alferd_Packer]

That the tests must be leaving something out?

Yeah, that the test were of "as sesigned" conditions, not "as Built" nor "as existing."

In other words, you are leaving out the effcts of the impacts on the fireproofing.



What's your point, anyway?

 

[jay howard]

Yeah, that the test were of "as sesigned" conditions, not "as Built" nor "as existing."

In other words, you are leaving out the effcts of the impacts on the fireproofing.

This is a notable point. As you well know, SFRM doesn't change anything about the structural properties of steel at ANY given location--it simply allows the steel to stay cooler for longer, thus retaining its strength longer.

Right? Nothing up my sleeve.

So, what's the only difference between near identical pieces of steel at 800C if one has SFRM and one does not? Not much.

The key difference is simply the amount of time it takes the SFRM steel to get to 800C. That's it. Steel strength is not affected by the SFRM. Once it reaches the same temp as the bare steel it has the same properties. Period.

So if you run a test long enough for the SFRM steel to reach temps far exceeding anything possible in the towers, then the results of that test (in terms of the behaviour of the steel) apply to bare steel at the same temp.

What's your point, anyway?

The point is: if you're looking to confirm what steel does at a particular temperature (say 600C) and you get the steel to 800C and it does NOT behave as your model predicted, then there is probably (but not certainly) something wrong with your model.

Can you agree with this?

.

 

[carlitos]

In terms of metatheory, would you agree that some bad dudes hijacked planes and flew them into the towers, and that there were no bombs in the building? Just for context. I mean no offense.

 

[jay howard]

In terms of metatheory, would you agree that some bad dudes hijacked planes and flew them into the towers, and that there were no bombs in the building? Just for context. I mean no offense.

This is an easy way to get distracted from what appears to be a fruitful discussion, but for the record, I have no reason not to believe the planes were hijacked by 19 guys for political/religious purposes.

The rest of it doesn't even matter until we get to the point of making sense of the NIST theory of collapse. If it makes sense all around, (accounting for all the available forensic evidence), then there's no need to speculate further.

If it does not make sense for some reason and it cannot be salvaged by ad hoc modifications, then it's time to look for a better theory. Until we pass that point, it does not make sense to invoke the "Evil Dwarves" theory that I have been itching to let loose on this thread like a pestilence of rational thought.

Joke. It's against my religion to use emotocons.

.

 

[Newtons Bit]

And since jay howard has missed it, I guess I'll explain. The purpose of the tests performed in NIST 1-5B were to verify that their thermal parameters and mesh size in the analysis were close enough to real behavior in a fire to be valid. And that's it. It was not to test the conclusion of the analysis.

 

[TruthersLie]

This is an easy way to get distracted from what appears to be a fruitful discussion, but for the record, I have no reason not to believe the planes were hijacked by 19 guys for political/religious purposes.

The rest of it doesn't even matter until we get to the point of making sense of the NIST theory of collapse. If it makes sense all around, (accounting for all the available forensic evidence), then there's no need to speculate further.

If it does not make sense for some reason and it cannot be salvaged by ad hoc modifications, then it's time to look for a better theory. Until we pass that point, it does not make sense to invoke the "Evil Dwarves" theory that I have been itching to let loose on this thread like a pestilence of rational thought.

Joke. It's against my religion to use emotocons.

.

Great.

Then present your thesis as to how NIST is wrong. Get it peer reviewed and published in ANY peer reviewed engineering journal and you will be the FIRST twoof.

It should be easy. I for one know that I would LOVE to read that paper... why are you wasting your time here?