Moderated Continuation - Why a one-way Crush down is not possible

ElMondoHummus said:
Tony, you're also missing the point that was made above, that NCSTAR 1-6D isn't a report on the actual construction of the towers. It's a discussion on the modeling, which includes the choices and tradeoffs they made in creating the computer model. They stated earlier that they only included the moment connections in the modeling and did something else to represent the other connections.
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I do understand they are only discussing the tradeoffs which they made in the model on the pages I cited.

However, there are very few places in the NIST report on the towers which discuss the central core beam connections to the core columns.
 
Tony Szamboti said:
The paper discusses failure due to compressive rupture, not buckling. Why would you be discussing buckling here? It sounds like you are intentionally distorting what was said in the paper and I really don't want to play your game.

Steel does strain harden once it is yielded and in the plastic region. Additional energy is required to cause additional strain.
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Push on a straw.
 
bill smith said:
These guys are just probing for weaknesses
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Doesn't really require much effort... Emphasizing on a failure mode that wasn't principally responsible in a collapse is one. The non-existant banana peel plumes "shooting up and out" are another... Denying visual indicators of buckling is yet another. Some of those errors are perhaps too easy to spot... :\
 
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bill smith said:
These guys are just probing for weaknesses I think. When is the debate Tony ?
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A couple of weeks ago it had been set for Sunday August 16th but the producer then came back and said the studio was closed on Sundays in August. So far we don't have a new date.
 
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Tony Szamboti said:
I have gone through NCSTAR 1-1 several times looking for core beam to column connection information and have not found any.

I would appreciate a reference.
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You didn't look real hard. Section 2.2.2 and 6.2 of NCSTAR1-1 explain quite clearly how there is no lateral restraint in the core above Floor 7.

There is also Requirement 303.700 from the original construction, found on Page 288 of NCSTAR1-1A, which states as follows:
Port Authority said:
Where box beams in this Contract connect to columns by means of a beam seat and top flange connection plate, the top flange connection plate may at the Contractor's option be shipped loose with the box beam. No shims for "loose" top flange connection plates are required.
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Does that sound like a moment-bearing connection to you?

Anyway, this also does not absolve you of your own burden of proof. You claimed that NIST "admitted" that "most" of the core beam connections took moments. This is false. You have not supported that claim. I'm under no obligation to show you that the opposite is definitely true, even though it's pretty easy to do so.
 
R.Mackey said:
You didn't look real hard. Section 2.2.2 and 6.2 of NCSTAR1-1 explain quite clearly how there is no lateral restraint in the core above Floor 7.

There is also Requirement 303.700 from the original construction, found on Page 288 of NCSTAR1-1A, which states as follows:


Does that sound like a moment-bearing connection to you?

Anyway, this also does not absolve you of your own burden of proof. You claimed that NIST "admitted" that "most" of the core beam connections took moments. This is false. You have not supported that claim. I'm under no obligation to show you that the opposite is definitely true, even though it's pretty easy to do so.
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Arguing moment frames and load paths with an "Engineer" who doesn't even know what the slope of the stress-strain curve means is a bit futile, don't you think?
 
Tony Szamboti said:
A couple of weeks ago it had been set for Sunday August 16th but the producer then came back and said the studio was closed on Sundays in August. So far we don't have a new date.
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I'm really curious how this show will work. It seems obvious that you will not be arguing about how a column connects to a beam on a TV show. Two engineers could end up arguing about the size of a bolt for the whole show. That wouldn't be very televisual. Give us a little advance warning when the show is to be taped if you can.
 
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rwguinn said:
Arguing moment frames and load paths with an "Engineer" who doesn't even know what the slope of the stress-strain curve means is a bit futile, don't you think?
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Probably. But I'm really hoping for an actually useful debate, so if I can get him past these kinds of stupid mistakes, everybody wins.

It's a bit dismaying that I can't, however.
 
R.Mackey said:
You didn't look real hard. Section 2.2.2 and 6.2 of NCSTAR1-1 explain quite clearly how there is no lateral restraint in the core above Floor 7.

There is also Requirement 303.700 from the original construction, found on Page 288 of NCSTAR1-1A, which states as follows:


Does that sound like a moment-bearing connection to you?

Anyway, this also does not absolve you of your own burden of proof. You claimed that NIST "admitted" that "most" of the core beam connections took moments. This is false. You have not supported that claim. I'm under no obligation to show you that the opposite is definitely true, even though it's pretty easy to do so.
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Anyone looking up the references you provided here will be Wowed at how much information is provided about the beam to column connections. All they are really discussing is that the exterior is depended on for lateral load resistance and not the core.

NIST is earily silent on the issue of beam connections in the core.
 
rwguinn said:
Arguing moment frames and load paths with an "Engineer" who doesn't even know what the slope of the stress-strain curve means is a bit futile, don't you think?
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You are obviously just blathering nonsense here apparently hoping somebody will trust you know what you are saying.

If you weren't you would explain where you think I was wrong. You don't though. Why not?
 
R.Mackey said:
Did you not read the requirement I quoted for you, or did you not understand it?
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The Requirement in the Appendix was vague also and does not qualify as a discussion of all core beam to column connections.

The NIST report is earily silent for the most part on these connections.

I think we need to stop this discussion between you and I here and save it for the debate.

In fact, I am going to refrain from posting on this forum until after the debate.
 
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