It's become evident that Tony feels no obligation to help his fellow truthers (in this case, Chris7) not make blatant, trivial mistaken claims.
He has shown the emptiness of his claim to be motivated by the truth. Instead, he seems enamored with Da Twoof.
So I'll answer the remainder of C7's mistakes here.
For convenience, I'll include the first 4 answers, that I've previously given, to allow either Tony or C7 to come back, refer to this one post, and not have to search for the previous ones.
I've highlighted Chris's adamant (and mistaken) assertions
in bold.
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1-9 Vol.1 pg 353
This analysis demonstrated possible failure mechanisms that were used to develop the leading collapse hypothesis further. The failure modes in this model were incorporated into the 16 story ANSYS and 47 story LS-DYNA analyses
Yes, this is what NIST says. But you are reading it incorrectly.
There were THREE models constructed: a preliminary FEA (ETA: which was also done in LS-DYNA -tk), the ANSYS model & the LS-DYNA model.
1. the preliminary FEA model: a static thermal / mechanical model of a single floor of the Northeast corner only.
The ONLY PURPOSE of this model was to help build the second model accurately. The first simple model helped the engineers determine which failure modes were likely (not definite!), and which components needed to be modeled in detail and which could be simplified.
This very simplified model ran for only 4 seconds (real time), and all the data needed for it came out in the first 3.
None of the failure modes or temperatures or effects seen in this model made any appearance in the final failure theory or summary.
2. the ANSYS model: a dynamic thermal & mechanical analysis of 16 lower floors.
The purpose of this model was to help determine the initiating event.
This model started with fires beginning in the SW corner of the building. It took about 3 hours (real time) for the fires to work their way around to the SE corner, and the rest of the results that are reported in NCSTAR1-9 start from the 3 hour mark.
The temperatures of all the components were determined by the FDS simulation. Nothing burned for any artificially long time, or at any artificially high temperatures.
3. the LS-DYNA model: a dynamic mechanical model (the thermal component was only to get the material properties correct at FDS calculated temps) of the whole building's response that started at the moment that c79 was unsupported. Note that all column buckling was calculated in this model.
The purpose of this model was to track the failure progression thru the building.
This model used the mechanical collapse output of the 2nd model (& temp profile from the FDS) as input, and then calculated the mechanical response of the building to the initiating mechanical failures thru total collapse.
All of the above is exactly appropriate for each failure analyses.
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Reading about the 1st two models should show you that the failure modes found in the preliminary analysis were not "incorporated" (as in "shoe-horned") into the ANSYS & LS-DYNA analyses.
Rather, the information gained in the preliminary analysis guided "what to look for", or "what options in the final analyses to enable".
It told them, for example, that in the ANSYS model, they had to model the studs independently (they couldn't assume them fixed to the concrete), they had to model the bolts & welds & connectors, and they had to allow the beams & girders to rotate & buckle.
These are all choices that are made in any FEA. And the more of these choices that you allow, the larger your degrees of freedom & the more complex & longer your analysis time.
The proof that this is true is that the ANSYS & LS-DYNA failure modes (girder pushed off seats, for example) were completely different from the preliminary analysis failure modes (torsional buckling of c44-c79 girder). Also the temperatures used in the ANSYS & LS-DYNA models were much lower than those used in the preliminary model.
However, I see a problem with GIGO in the subsequent analyses. There are numerous fraudulent aspects in the "rock to the east" analysis.
There are precisely zero "fraudulent aspect" of the preliminary model. There is merely your ignorance of how engineers perform failure analyses.
The preliminary analysis (i.e., "Rock to the east" model) is irrelevant to the final conclusions. It simply informed the engineers which issues were significant issues and which issues were insignificant.
Note that the preliminary analysis was INTENDED to highlight, to exaggerate the effects that were likely to occur in this specific structure. So they intentionally select conditions that were extreme, to see what broke & how it broke.
The final failure mode analysis, the ANSYS model, used the results of the first model to determine which components had to be modeled in detail & which components could be simplified.
This is standard engineering failure analysis.
It is "fraudulent" only to the clueless.
The preliminary model was NOT the basis for their conclusions.
The final (ANSYS) model was the bases for their conclusions.
As they say explicitly:
NIST said:
The boundary conditions and temperatures were selected to create maximum shear forces on the stud connectors and beam and girder connections. Note that, in the detailed finite element analyses of the 16-story ANSYS model (see Chapter 11), no boundary conditions were applied to the floor slabs, and the temperatures of both the steel and concrete were derived from a thermal analysis based on fire dynamics calculations.
NCSTAR1-9 vol 1, pg 349
1) they applied 4 hours of heat at 1100oF but the fires only burned for 20 to 30 minutes in any location
This statement is simply false.
Nowhere in any NIST analysis was any temp set at 1000°F & held for 4 hours. I find it incredibly difficult to believe at this late date that someone hasn't already called you on this error / fabrication.
You are, accidentally or intentionally, conflating two different analyses.
1. In the preliminary analysis (which contributed nothing to the final failure causes):
a) they ramped the temperatures up from room temp to max temp over the course of about 2.5 seconds & watched the effects for around 4 seconds. They were looking at static response of the components, not dynamic response, so this technique is completely valid. (NCSTAR1-9, Fig 8-25)
b) the max beam temps ramped to 600°C (1100°F) & girder temps ramped to 500°C (930°F). This was a short cut and they intentionally set the temperatures too high for this preliminary analysis.
b) they only needed to perform about 3 seconds of analysis time before they got the information that they were after. (See Table 8-2). None of the failure modes discovered here were included in the final "what caused the collapse" summary.
2. In the ANSYS model (which were the basis for the final failure summary):
a) the temps in all components were calculated, the result of their Fire Dynamics Simulator, based on many local conditions such as office contents, fuel load, oxygen flows, etc. These temps were not set to exactly 500° (beams) or 600°C (girders), but rather ranged between 150° to 700°C, depending on time, location & fire conditions.
b) the 4 hours was from the start of the fire (in the SW corner) to the buckling of col 79. The heating in the Eastern side of the building did not start until 3 hours into the simulation, when the fires in the SE corner were just starting.
2) they heated the entire area all at once but that is not what happened in the actual fire.
Wrong in both cases.
In the preliminary case, they ramped up the temp over 2.5 seconds. This was a static analysis so the ramp time does not matter.
In the ANSYS case, they ramped the temp UP & DOWN, locally & dynamically, as calculated by the FDS software. To the best of this software's ability, this is exactly how fast, how long & how hot the temperatures actually rose in each modeled component in the building. With a couple of simplifying assumptions that were verified thru detailed thermal analysis.
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3) They applied that 4 hours of heat in 1.5 seconds giving a false result. That did not allow the beams to sag which they would have done because the bottom flange would be hotter that the top flange. It also did not allow for heat dispersal thru the slab and to other structural members.
Nobody applied 4.5 hours of heat to anything.
You are still, out of incompetence or mendacity, conflating 2 separate analyses.
See above for correct application of temperatures in the two separate analyses.
4) They heated the beam but not the slab to get the shear studs to fail. That gave a false, excessive temperature differential.
They did this in the preliminary model.
Not in the ANSYS model, in which they put in break elements at each stud, and let the concrete & beam temperatures rise as the FDS calculated.
It did NOT give a false excessive temperature differential.
The thermal conductivity of the concrete is so much lower than that of the steel, that the steel will expand fully before the bulk (i.e., vertical midpoint) of concrete has even begun to expand. This will shear the stud promptly during the heat up phase. It doesn't matter if the expansion of the concrete eventually catches up to the expansion of the beam, the fracture has already occurred.
The simplifying assumption that NIST used
for the preliminary analysis only is absolutely the correct method of getting a quick assessment of the survival of the studs.
I know that this has been explained to C7 before, because I explained it.
5) they lied about the width of the seat.
This has been put to bed.
There was a typo in the transcript.
They use the right dimension in their analysis.
Has C7 retracted his claim of "lying & fraud", yet?
6) once the bolts on the seat and top clip had broken there would be no axial restraint on the beams on that end so they would not buckle.
NIST cites three mechanisms that led to buckling:
1. Torsional forces that twisted the beam or girder about its horizontal axis ("lateral-torsional buckling"). See NCSTAR1-9 v2, pg. 487.
2. Axial compression due to restrained thermal expansion.
What you say about the end bolts contribution to axial compression and buckling is mostly true, and mostly born out in NIST's report (see below). Except …
2a. Axial compression buckling could happen after bolts sheared on seated connections if the beam or girder expanded enough to contact a supported column & the column provided end restraint. This only occurred (AFAIK) in the preliminary model. I have not seen anywhere in the ANSYS analysis where NIST claimed that this happened.
3. Loss of beam stiffness due to heating & gravity loads.
The buckling that you are referring to only addresses mechanism #2, so a beam or girder with its end bolts fractured could still buckle by mechanisms 1 or 3 (or 2a).
That being said, if you go thru all the diagrams of the state of beams (11-22 thru 11-44), you'll notice that
most of buckled beams (pink lines, see legend) do have at least partial bolt integrity at both ends.
As for your "fraudulently buckled" components, you'll have to be more clear about which member and about which analysis you're talking.
Specifically in the analysis that mattered (ANSYS), NIST never claimed that the girder between c79 & c44 buckled.
7) they left out the three short cross beams between the exterior wall and the northmost floor beam as well a one more between that beam and the next. It would not have buckled sideways but downward.
The three beams between the exterior wall & the northern most floor beam are so far away from the action (at c79) and so close to fixed components (the external membrane frame) that they are irrelevant. In the ANSYS analysis, that beam did not buckle.
The extra cross beam that you are referring to shows up in fig. 8-16 (frankel steel erection drawing) & 8-18 (Cantor structural drawing). It does not show up in the flooring plan drawings, fig 2-3 thru 2-13.
Resolution regarding existence or not: unknown.
Effect on results: none.
Once again, look at fig 11-35 & fig 11-43:
none of those beams attached to these cross beam buckled in the ANSYS analysis, so your objection that "they wouldn't have buckled if they included these cross beams" is moot.
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And that's it.
Every one of Sarns' claims of NIST's fraud or incompetence … is simply wrong.
Or, a typo.
And in one case (the last one), an irrelevant appeal to perfection in an FEA model that is completely beyond his grasp.
Once again, like all the other times before, a Truther's "gotcha" evaporates when one reads and understands what the NIST engineers really wrote.
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Tony, C7: if you'd care to comment at this point, be my guest.
tk
