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WTC7 and the girder walk-off between column 79 and 44

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It's become evident that Tony feels no obligation to help his fellow truthers (in this case, Chris7) not make blatant, trivial mistaken claims.
...................................

Tony, C7: if you'd care to comment at this point, be my guest.

tk

Thanks. Excellent summary.
Tony would say your arguments are so good someone must be paying you to exhaust him, and that Oystein must still be working for the Stasi, to harass him.
It's Mackey's Inflationary model.
 
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That's funny and incredible all at one time. It never fails to amuse when someone makes a claim that someone else is wrong without showing why. I would say you are the real gasser here.

Hypocritical? Isn't that why you're doing an analysis now? :rolleyes:
 
...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.
.........

Tony, C7: if you'd care to comment at this point, be my guest.

tk
Thanks for that summary tfk. It gives me a clear reminder of the overall setting for this topic.

As you know early in this thread I was one of those who, like you and a few others, identified the underlying flaws in the main assumptions adopted by C7 and later taken up by TSz.

I then became more explicit in the areas where T Sz's claim was deficient whilst insisting that it was his 'burden of proof' to support his claim.

The only progress I see is Tony's recent acknowledgement that the assumption of unchanged end conditions for the subject girder needed to be addressed. Given his earlier denials of the need to address it AND his subsequent 'bold assertions' that it had been we are seeing one step forward.

Whether his explanation is satisfactory remains in serious doubt given the true situation with NIST's work as shown by your summary.

And there are still the other concerns we have raised lying in wait...

The NIST walk-off explanation remains plausible and the default hypothesis.

And whether or not NIST's explanation was correct it has no effect on claims for CD. What happened on 9/11 happened and no report written years later can change historic fact.
 
Hypocritical? Isn't that why you're doing an analysis now? :rolleyes:

You don't seem to be paying attention. The hypothesis I am analyzing is an axial walk-off which was proposed by some here, most notably BasqueArch. It is not the mechanism NIST alleged precipitated the collapse. The NIST mechanism (lateral walk-off) has been shown to be impossible.
 
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You don't seem to be paying attention. The hypothesis I am analyzing is an axial walk-off which was proposed by some here, most notably BasqueArch. It is not the mechanism NIST alleged precipitated the collapse. The NIST mechanism (lateral walk-off) has been shown to be impossible.

Shown to be impossible how, by posting crap on JREF?
 
Shown to be impossible how, by posting crap on JREF?

Somebody has a pretty broad definition of "shown to be impossible"

It has been shown that the NIST lateral walk-off collapse mechanism for WTC 7 is impossible since

- the recently released drawings 1091 and 9114 show the 11.510" wide W33 x 130 girder sat in a centered position on a 12" wide seat at column 79.

- with the stiffeners omitted in the NIST report, but which we now know were on the girder due to the release of drawing 9114, it could not fall from the seat due to lateral movement until it was pushed at least 9" to the west.

- the 53 foot long beams could not expand and push the girder laterally to the west more than 5" no matter what temperature they reached.

- NIST says that column 79 was laterally unsupported in the south and west between floors 5 and 14 before the alleged walk-off of the girder to the north at floor 13, and the west side girder between columns 79 and 76 at the 14th floor cannot possibly push the column to the east enough at the 13th floor to make up the difference.

If you can't show how the beams to the east could push the girder between columns 44 and 79 at the 13th floor off its 12" wide seat at column 79 with the stiffeners on the girder as shown in drawing 9114 then your comments here amount to nothing but whining about it.
 
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homer-face-palm.jpg
 
You don't seem to be paying attention. The hypothesis I am analyzing is an axial walk-off which was proposed by some here, most notably BasqueArch. It is not the mechanism NIST alleged precipitated the collapse. The NIST mechanism (lateral walk-off) has been shown to be impossible.

No it hasn't. Fire caused the collapse. To believe fire can't hurt an already damaged building is a dangerous, ignorant, stupid thought. You failed before you started writing on your first napkin. No math needed. You're welcome. :D
 
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The one constant that Tony has shown repeatedly in his various analyses is that he possesses the engineering JUDGMENT of a mediocre first year engineering student. If he is handed the correct equation, then he is able to plug the numbers into a calculator or spreadsheet & accurately relate the answers that those two tools may provide. (God knows that he can't derive the correct equations himself, as the circle jerk with Moment of Inertia - and a dozen other exercises - have shown.)

[Pedantic mode on]
However an engineers greatest asset, one that comes with experience, is judgment. It is the ability to look at things in a meaningful way, to be able to discern the important factors from the unimportant, and to possess a "feel" for (in the case of mechanical engineers) how the various components are going to mechanically interact.
[/Pedantic mode]

This exercise is another great example of Tony's failure in this regard.

A couple of drawings to show what really goes on after the c79 - c44 girder has slid about 6.4" (not straight to the west, but) perpendicular to the axis of the girder, which is slightly north of west.

I've done one modification to the parts in these drawings: I've trimmed away the thin segments of metal from the girder seat and the girder that were incapable of supporting the structural loads of the girder.

I trimmed the seat where it overhung the support plate. And I've trimmed away the bottom & top flanges of the girder where they overhung the stiffener plates. The only reason that I removed the top flange segment is simply to allow visualization of the bottom flange segment when looking at a top view of the assembly.

Tony has already agreed that these components would have been unable to support the structural load of the Girder, which supported the entire northeast corner of the 13th floor. Trimming away these segments is exactly equivalent to retaining columns, beams, joists, etc. in a structural drawing, while removing wall board.

Here is the top view of the assembly with the girder slid 6.4 inches by thermal expansion of the floor beams. The various components are labeled. I chose 6.4" of slide because it was slightly greater than the 6.29" that would have brought the beam's central web into alignment with the end of the seat.



picture.php

Top View: Column 79 & Girder Seat Assembly, 6.4" of girder slide



Here is a bottom oblique view of the same situation.


picture.php

Bottom Oblique View: Column 79 & Girder Seat Assembly, 6.4" of girder slide


Here is a detail view of the Girder, seat & support plate interface with the "load bearing capable" area shown in red.


picture.php

Detail, Top View, Contact Load Bearing Area (Red)


Take a look at this load bearing contact area (red area) in the detail view, and then look back at the whole assembly in the first, Top view.

Realize that this small triangular sliver of metal is attempting to support the entire weight of the Northeast quadrant of the 13th floor. All the weight that tied into that girder.

The situation described above is one that Tony asserts is "proven impossible for the girder to collapse until it slides an additional 2.6" more (9" total)." He asserts this, vigorously, because a couple lines overlap on a piece of paper.

This amounts to "The Delusion of the Infinitely Strong Line on an Assembly Drawing".

Combined with "The Delusion that Everything Stays Exactly Where You Want It, No Matter How Poorly Supported".

Engineering students & Baby Engineers with little experience often fall prey to these delusions.

Seasoned engineers, those with experience & judgment, know better.


Tom


PS.
A couple of important notes on this assembly drawing: I drew all components in their "nominal position".

(In order of significance in increasing or decreasing the contact area)

1. I've not accounted for any motion in any direction of the column.

2. I've not allowed for any sag of the girder due to load (NIST reports 2.5" sag due to concrete weight alone, IIRC. I don't recall that they calculated deflection of the composite Girder/concrete floor due to live load.) This shortening would pull the end of the girder further off of the seat to the north (towards the bottom in the drawings).

3. Similarly I've not accounted for any thermal expansion of the girder.

4. I've not accounted for any tolerance errors in any of the components or features.

5. I've not allowed for any clean up chamfers on the top edge of the support plate.
 
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(In order of significance in increasing or decreasing the contact area)

1. I've not accounted for any motion in any direction of the column.

2. I've not allowed for any sag of the girder due to load (NIST reports 2.5" sag due to concrete weight alone, IIRC. I don't recall that they calculated deflection of the composite Girder/concrete floor due to live load.) This shortening would pull the end of the girder further off of the seat to the north (towards the bottom in the drawings).

3. Similarly I've not accounted for any thermal expansion of the girder.

4. I've not accounted for any tolerance errors in any of the components or features.

5. I've not allowed for any clean up chamfers on the top edge of the support plate.

By your own admission your pictorial has the girder at ambient temperature while the beams would have to be at 600 degrees C to even get 4.5 inches of expansion. If you are supporting the NIST theory you need to add another 1.61 inches back onto each end of the girder to account for it's expansion at the 500 degree C temperature they say it was at. The support plate was 2 inches thick so one can see that this 1.61 inches puts the flange stiffener area well over the support plate under the seat.

The girder would not be at ambient temperature in any scenario where it was being pushed by adjacent structural members at 600 degrees C. The reality is that if you showed the girder at 500 degrees C, with the associated 1.61 inches of expansion at each end, you would see that even with 9 inches of westward translation relative to the seat that a significant portion of the girder stiffener area would still be over the support plate.

You really should stop denying the reality that the NIST collapse initiation scenario for WTC 7 is an impossibility, as it is starting to get silly now.
 
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1. I've not accounted for any motion in any direction of the column.

2. I've not allowed for any sag of the girder due to load (NIST reports 2.5" sag due to concrete weight alone, IIRC. I don't recall that they calculated deflection of the composite Girder/concrete floor due to live load.) This shortening would pull the end of the girder further off of the seat to the north (towards the bottom in the drawings).

Just go ahead and ignore these Tony.
 
Just go ahead and ignore these Tony.

I am glad you brought it up so I can explain why they are inconsequential and probably why TFK did not quantify them for you.

I have already shown that column 79 could not be deflected to any significant degree to the east at the 13th floor by the girder between columns 79 and 76 at the 14th floor. Did you notice that TFK did not counter that after I explained that the only girder available to push column 79 to the east was at the 14th floor? Being hot it would have buckled at about 80,000 lbs. of force and wouldn't have pushed column 79 more than about a half inch maximum with much less deflection than that seen 13 feet down at the 13th floor. This one is a big downer for TFK's theories.

The amount of shortening of a 547 inch long girder that has been deflected 2.5 inches downward is all of about 0.040 inches. That would also be split about both sides, so it would only be about 0.020 inches on one end.

In reality, the girder's thermal expansion was the most significant effect TFK did not consider and is what made his analysis unrealistic and invalid.
 
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By your own admission your pictorial has the girder at ambient temperature while the beams would have to be at 600 degrees C to even get 4.5 inches of expansion. If you are supporting the NIST theory you need to add another 1.61 inches back onto each end of the girder to account for it's expansion at the 500 degree C temperature they say it was at. The support plate was 2 inches thick so one can see that this 1.61 inches puts the flange stiffener area well over the support plate under the seat.

The girder would not be at ambient temperature in any scenario where it was being pushed by adjacent structural members at 600 degrees C. The reality is that if you showed the girder at 500 degrees C, with the associated 1.61 inches of expansion at each end, you would see that even with 9 inches of westward translation relative to the seat that a significant portion of the girder stiffener area would still be over the support plate.

You really should stop denying the reality that the NIST collapse initiation scenario for WTC 7 is an impossibility, as it is starting to get silly now.

You don't know what you're talking about.

Even after explaining it to you in painful detail, you still don't comprehend.

You are still quoting the PRELIMINARY FEA temperatures. (500°C for the girders, 600°C for the beams).

These temps had NOTHING TO DO with the temps that NIST says that any of the girders, beams, columns or connectors reached.

NIST NEVER said that the c79 - c44 girder reached 500°C, Tony.
The temps that NIST says that any particular component reached is listed in the ANSYS model. Not the preliminary model.

How many times does one have to explain a trivial simple concept to you, Tony, before it sinks in??

Look at Figure 11–46. Floor 13 Case B temperatures at 3.0 h, 3.5 h, and 4.0 h.

Temp of c79 - c44 girder:
3.0 hrs: 75°C
3.5 hrs: 100°C
4.0 hrs: 150°C (tops)

Note that Case B was the hottest case.

Christ on a bicycle.
"... 500° C ..."

No, Tony. Somewhere between 100°C & 150°C.

Rerun your elongation for that delta t above ambient.

Then address the other 4 factors that could (& would) make it pull back off of the seat...

I'm done with your foolishness.

You can't get a damn thing right ...
... but "you've proven NIST analysis to be impossible"??

Sure thing, Tony.
Whatever you say.
:rolleyes:
 
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You don't know what you're talking about.

Even after explaining it to you in painful detail, you still don't comprehend.

You are still quoting the PRELIMINARY FEA temperatures. (500°C for the girders, 600°C for the beams).

These temps had NOTHING TO DO with the temps that NIST says that any of the girders, beams, columns or connectors reached.

NIST NEVER said that the c79 - c44 girder reached 500°C, Tony.
The temps that NIST says that any particular component reached is listed in the ANSYS model. Not the preliminary model.

How many times does one have to explain a trivial simple concept to you, Tony, before it sinks in??

Look at Figure 11–46. Floor 13 Case B temperatures at 3.0 h, 3.5 h, and 4.0 h.

Temp of c79 - c44 girder:
3.0 hrs: 75°C
3.5 hrs: 100°C
4.0 hrs: 150°C (tops)

Note that Case B was the hottest case.

Christ on a bicycle.
"... 500° C ..."

No, Tony. Somewhere between 100°C & 150°C.

Rerun your elongation for that delta t above ambient.

Then address the other 4 factors that could (& would) make it pull back off of the seat...

I'm done with your foolishness.

You can't get a damn thing right ...
... but "you've proven NIST analysis to be impossible"??

Sure thing, Tony.
Whatever you say.
:rolleyes:

Okay Tom. We will do it your way.

Figure 11-46 shows the girder at about 225 degrees C and the beams at an average of about 350 degrees C. In this situation the beams expand about 2.5 inches and the girder about 1.25 inches.

So shorten up your westward beam expansion to 2.5 inches and add 0.625 to the end of the girder and see what you get. Guaranteed there will be plenty of girder stiffener and even the web over the support plate.

Your analysis is invalid and the NIST collapse initiation scenario for WTC 7 is impossible no matter which way they are looked at.
 
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Funny how these 911 cult kiddies are always trying to say NIST is wrong, NIST is telling lies, NIST is trying to fool people.

Yet it's not NIST that is roaming the internet, pestering people into joining their beliefs, it's not NIST handing out alex jones dvds and ae911 pamphlets on street corners. It's not NIST running around calling people shills if you don't join them.
 
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