Yeah the group researched and continues to. I'm just making the point we can all speak for ourselves too. Like I am doing here.What happened to the genuine research group ?
Yeah the group researched and continues to. I'm just making the point we can all speak for ourselves too. Like I am doing here.What happened to the genuine research group ?
The mistake was not "stopped" by NIST, it was called to their attention and they had to issue an erratum on it. And I don't think I am important, the information is, and putting the NIST reported analysis under scrutiny is.
Yeah the group researched and continues to. I'm just making the point we can all speak for ourselves too. Like I am doing here.
So you are hoping for a new investigation with a different result ?
Would you agree fire, connection failiure and beam/girder faliure is a good probable cause ? If not what would you be looking for in your outcome.
In your fantasy world, where that matters - how would the conclusion (Fire+Damage = Collapse) change if they reported those numbers correctly?
It has been pretty obvious for a long time that there is no interest by either he or his "group" to do anything except continue the hamster wheel "discussion"
Dicky gage can continue his expense paid vacations for the foreseeable future.
Meanwhile, our two current troofer posters can run back to the safe haven forums and just bump each other.......all the while not having a clue about building structures or computer modelling![]()
Two very simple questions then.
Why did NIST mention column displacement?
What makes it so definitive that it occurred after girder walk off since NIST does not specify that?
What happened to the genuine research group ?
Yeah the group researched and continues to. I'm just making the point we can all speak for ourselves too. Like I am doing here.
???? Ziggi
I outlined reasoning to support the idea that it was prior to walk off.
Your contention is that it occurred after walk off because NIST doesn't specify exactly when it occurred.
It would seem then that for you it must have occurred after walk off because that's when you want it to.
In your fantasy world, where that matters - how would the conclusion (Fire+Damage = Collapse) change if they reported those numbers correctly?
NIST mentions the column displacement because it is listing events that happened within the 4 hour mark, that´s all.
The problem for you is not that NIST does not specify exactly when the column displacement occurred, the problem for you is that NIST does not claim anywhere that this event aided the girder walk off, as you ASSUME. The 11.6 summary is there for a reason.
The 13th floor C79-44 girder failed due to lateral-torsional buckling. The top flange and web rotated past their load carrying geometry, past the seat edge. You have nothing.NIST had to admit to a crucial part of their report being the wrong way round. They also had to admit getting 11" mixed up with 1 foot, and all this at what must have been one of the most heavily scrutinized parts of the report inside NIST. You're saying they passed wind when in fact they had a massive dump.
No, making NIST seem infallible is your task at hand, and I don't envy you it at all. Their difficulty in differentiating between numbers isn't a good start in the infallibility stakes.
My gran used to read that. NISTs technical briefing was a bit more technical, but in reality was just more specific about the same errors.
And this is you defending the report?
You're only talking to me here. I am not speaking on behalf of any group. As for weaving together compelling scenarios, the score would remain 0-0 at the moment.
It does, and it hasn't.
The mistake was not "stopped" by NIST, it was called to their attention and they had to issue an erratum on it. And I don't think I am important, the information is, and putting the NIST reported analysis under scrutiny is.
NIST called it in depth, you compare it to a magazine. Either way it belongs in the fiction section.
The reason given for not including them was that they were designed to help prevent web crippling. Are you saying that they would not also help prevent the bottom flange from folding?
Not as well as I'd like, no.
I wish I shared your confidence.![]()
NIST mentions the column displacement because it is listing events that happened within the 4 hour mark, that´s all.
The problem for you is not that NIST does not specify exactly when the column displacement occurred, the problem for you is that NIST does not claim anywhere that this event aided the girder walk off, as you ASSUME. The 11.6 summary is there for a reason.
You didn't read my post or if you did you didn't understand it. Your post has too many engineering incompetent errors to correct. NIST proved fire and not explosives collapsed WTC7.Ziggi
BasqueArch and others are still falsely presenting chapter 8 as NIST´s walk off theory, even though it has nothing to do with it. Chapter 8 shows an entirely fictional scenario designed to get the sheer studs to fail, see page 346. This fictional scenario included heating the beams to 600C in 1.5 seconds while the floor slab is cold, to maximize the stress on the sheer studs. This is of course impossible in the real world, and NIST´s fire simulation, but is irrevelant here because this experiment relies on neither.
Chapter 10 introduces the fire simulation, where the heating occurs over several hours not seconds, and chapter 11 introduces the walk off theory based on results from chapter 10, which is completely different from the fictional "girder rock event" shown in chapter 8.
The rock off shown in chapter 8 is not even based on the fire simulation, and it shows the floor beams buckling so they pull the girder axally straight back to the westward direction. The real walk off theory is based on the fire simulation and it shows lateral not axial displacement, because the floor beams are expanding and pushing, instead of buckling and falling back, and the result is displacement to the east not the west.
Trying to conflate these two scenarios is pure gobbledygook.
If you want to learn about NIST´s walk off theory, go to chapter 11.
NIST mentions the column displacement because it is listing events that happened within the 4 hour mark, that´s all.
The problem for you is not that NIST does not specify exactly when the column displacement occurred, the problem for you is that NIST does not claim anywhere that this event aided the girder walk off, as you ASSUME. The 11.6 summary is there for a reason.
You're still dodging the question, Ziggi.
How, in your opinion, should NIST have reported the walk-off that ANSYS showed, to meet your standards of scientific quality?
Let's leave apart for a moment that the report passed peer review from engineers. Let's focus only on what you expect from them in order to consider the report scientific when reporting the walk-off. What should it have said?
ANSYS didn't show a walk off as such. The girder was displaced to the point that NIST deemed if to have failed. This is an important distinction and illustrates that NIST set the walk off points for such elements outwith ANSYS.
"Therefore, when the web was no longer supported by the bearing seat, the beam was assumed to have lost support, as the flexural stiffness of the bottom flange was assumed to be insufficient for transferring the gravity loads."
NIST´s model/results are based on a series of assumptions. There is no analysis or simulation to show the expansion, or the girder walk off, or to prove that the flange would fold once the web was past the seat plate. As I mentioned in post 4052, NIST says that:
NIST never said the beams expanded more than 6.25". They said the beams pushed the girder off the seat.Ziggi
............The simulation showed that the floor beams could be heated to 600C, and if you plug that into NIST´s expansion equation, you end up with 5.5 inches of expansion plus change. At this point NIST had a valid input point for the computer model to report walk off, given the wrong 11 inch seat width and forgotten stiffener plates , and NIST could have clearly explained this in the report as I am asking for. ......
I'd frankly like to know the essence of what this meta detail is supposed to conclude. If the NIST got the girder walk off wrong, then what? Are you contending based on this that the code recommendations they make based on their conclusions are wrong?
...You're spending so much time doing this that it seems to me like you're not getting your point across. Disagreeing with NIST on whether the girder walk off was sufficient or not isn't unrealistic per se, but I can't figure out from your over-focus on this level of detail where your criticism leads...