AE911 Truth's WTC7 Evaluation Computer Modelling Project

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Is the error in NIST's global model or did they correct it as well?

It's hard to think highly of Hulsey's "diligence" after discovering he plagiarized portions of his initial presentation from anonymous conspiracy theory blogs, including portions dealing with key subjects about which he is purportedly an expert--steel in fires (if not according to his resume and experience, then at least according to AE911Truth's puffery)? His "diligence" also didn't stop him from apparently testing the wrong measure of displacement for column 79, nor did it stop him from making from making false claims about the how NIST modeled the exterior, connections in the LS-DYNA model, and side plates. Maybe his assistants were more diligent in the weeds on the project, but Hulsey has not done his due diligence on NIST's model and it seems he has led the project down some questionable paths as a result.
Be clear here please Bentham. You wrote.. "making false claims about the how NIST modeled the exterior, connections in the LS-DYNA model"
Are you aware of any errors that existed in LSDYNA that were NOT carried over from ANSYS ?
I guess the stiffener plates were shown on one model. I think that was ANSYS, but then disappeared from the LSDYNA model (perhaps you can correct me if I have that the wrong way round).
I would guess the only excuse for NIST there could be that different people did different models, so didn't check. Continuity issue there though.
 
On the measure of displacement thing, I can see how that could perhaps be made more clear for an audience new to the topic,

Okay, so how would you explain the comparison of his 2" to NIST's 5.5" for an audience new to the topic?


20170916-182149-psgy6.jpg
Briefly state what the two number represent, and what the difference means, and what it means to "our calculations"
 
Okay, so how would you explain the comparison of his 2" to NIST's 5.5" for an audience new to the topic?

Hang on Mick, sure, I will give you my take on that right after you let me know about [where]NIST's centre of stiffness [is]and your take on it.

[off topic commentary removed]
 
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@gerrycan do you know if Xaio (apologies if I'm misspelling) is still actively working on the project or did he stop when he moved to wherever he's working now.
 
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What I don't understand is why Gerry and Tony are defending this tbh. Or better yet, I don't understand WHAT they are defending, since there is still no report from Hulsey. It seems to me that the only thing they care about is that the result says NIST is wrong. How the result was established does not matter it seems.
 
Okay, so how would you explain the comparison of his 2" to NIST's 5.5" for an audience new to the topic?


20170916-182149-psgy6.jpg
Briefly state what the two number represent, and what the difference means, and what it means to "our calculations"
Mick I replied to you and it got deleted. It was a totally pertinent and fair question.
We CANNOT debate in this way. It's unfair. Sorry

Funny that. I asked you the question in post #800 and that wasn't deleted for being "off topic"
You are scared of debate. This makes it look as if you CANNOT answer that question about the centre of stiffness, and instead of admitting that, you got it deleted.
You've been doing that to Tony and many others. You pick and choose the rules and when to enforce them to suit. That isn't how debates work.
Debate me in an open and fair forum, and see how you get on there ?

Edit add - To ask you where the centre of stiffness is located in the only other FEA model published about this building in order to ascertain whether it concurs with the UAF model is surely ON topic.
How can that possibly be off topic ? It's a measure of the building.
 
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Yes. As I said it appears to be a copy of a sheet or two that was sloppy in the drawings that NIST decided to release.
I believe it is raised as an issue in the work diary somewhere, and the result would clearly be to have the columns concerned to align top to bottom.

Shows just how capable UAF are, and that they went through the original released drawings and in so doing shed light on this error in the drawings that NIST released.

I am sure you will join me in admiring their due diligence.
If it's the drawings in Zhili's work diary you're referring to, they look like building blueprints/floorplans, do we know that NIST created them and if so how?

If not, and they are the original architect drawings, I would expect NIST to release those originals.

Ray Von
 
If it's the drawings in Zhili's work diary you're referring to, they look like building blueprints/floorplans, do we know that NIST created them and if so how?

If not, and they are the original architect drawings, I would expect NIST to release those originals.

Ray Von

No. I am referring to the structural drawings that were released for the building. the originals. Not architectural (i think you're using the term interchangeably).
The error itself isn't really serious as it would be entirely obvious in reality where the column was to be. ie straight line.
And yes, I agree, NIST should release all the drawings that they have for WTC7. Also, they should release the structural drawings for the towers.
 
To ask you where the centre of stiffness is located in the only other FEA model published about this building in order to ascertain whether it concurs with the UAF model is surely ON topic.
that's not what you asked. and I'm the one that deleted that comment. (now ill go read comment 800 and see if I missed it).

THIS convo is off topic too Gerry can. This thread is already 21 pages long! SOME people, like me, are not interested in "debate", we are interested in finding actual information. ALL MEMBERS, try to keep this in mind when posting.

Cryptic comments are not the only problem, repetitive back and forths (from other members) clog up the thread too.


add: I fixed your comment and undeleted it @gerrycan , but I am not your secretary. Write better comments in the future please.
 
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Hang on Mick, sure, I will give you my take on that right after you let me know about [where]NIST's centre of stiffness [is]and your take on it.

Let's say for now I'm just a general audience with a reasonable grasp of math, physics, and the geometry of WTC7.

Then explain how the two value are comparable.

Hulsey made that comparison as a major point in his presentation, right before he said: "No, (this is based on our calculations)"



Surely this important point deserves explanation? But until you do explain it we can only assume the comparison is meaningless.
 
Let's say for now I'm just a general audience with a reasonable grasp of math, physics, and the geometry of WTC7.
Yeah. let's just say that. Fair comment.

Then explain how the two value are comparable.
They show the difference between the 2 models and approaches. I do agree that this particular part requires a more in depth explanation attached to it.

Hulsey made that comparison as a major point in his presentation, right before he said: "No, (this is based on our calculations)"

Ok. So NIST get 5.5" movement to the west by the girder relative to the column.
UAF get around 1.9" East in their model when the building is modelled as per the drawings.

The whole thing moves relative to the stiffness centre. We don't have that value examined by NIST, unless you can enlighten me on that. It's important to know. Do you agree that the centre of stiffness is actually the correct place to express movement in the building relative to ?

Surely this important point deserves explanation? But until you do explain it we can only assume the comparison is meaningless.

Are you aware of NIST expressing anything about the centre of stiffness in the building?

When the building system is composite, it moves together. When UAF did a smaller scale simulation to test NIST's claim by replicating their conditions and elements, They got 5.1" movement to the West in the girder relative to the column.
ADD This is only 0.4" short of NIST's original claim, and proves that the elements and the way the building is modelled makes a difference.
Which approach do you think is correct ?
 
Ok. So NIST get 5.5" movement to the west by the girder relative to the column.
UAF get around 1.9" East in their model when the building is modelled as per the drawings.

The whole thing moves relative to the stiffness centre. We don't have that value examined by NIST, unless you can enlighten me on that. It's important to know. Do you agree that the centre of stiffness is actually the correct place to express movement in the building relative to ?

It depends on exactly what you are examining. The issue being discussed was if the girder walked off its seat. So the relevant movement is that of the girder relative to the seat.

More broadly, movement relative to a center of stiffness of the building is pretty much irrelevant when it comes to connection failure. It's the difference in motion between two connected parts (i.e. the relative motion) that leads to connection failure.

These are measures of different things. So do you agree they are not comparable, and that Hulsey has mistakenly presented them as if a direct comparison has meaning?

And are you saying that in reality there was no relative motion at any of the connections?
 
I'm a little unclear about the relevance of the movement relative to a "center of stiffness" at all. All the movements are equally relative to any fixed point - essentially it's a movement relative to a fixed frame of reference, not a point.

So why is the position of the center of stiffness relevant? If I picked a random point on the ground then would the numbers be any different?
 
It depends on exactly what you are examining. The issue being discussed was if the girder walked off its seat. So the relevant movement is that of the girder relative to the seat.
No. We are examining the building. And yes, the movement of the girder relative to the seat is what NIST alleged initiated the failure.

More broadly, movement relative to a center of stiffness of the building is pretty much irrelevant when it comes to connection failure. It's the difference in motion between two connected parts (i.e. the relative motion) that leads to connection failure.
That is not the wisest thing you have ever said Mick. In essence you are trying to promote the idea that relative movement counts, but where the elements start from is not important. You should think about the above statement. It's telling.

These are measures of different things. So do you agree they are not comparable, and that Hulsey has mistakenly presented them as if a direct comparison has meaning?

You might as well be arguing that the 2 FEA's are not comparable because one of them modelled the building as per the drawings and one did not. It certainly wasn't NIST that got it right and you know that. You have looked at the drawings. But still, you cannot bring yourself to admit it clearly. Also very telling.

And are you saying that in reality there was no relative motion at any of the connections?
No. Not saying that. Never said that. Wouldn't say that.
On the whole, the point of comparison needs more explanation as far as the UAF project goes, but the difference in the 2 approaches is worth noting. Things do expand from their stiffest point. ie a beam pinned at one side will expand toward the other. Change the pinned side and it will expand in the opposite direction. Where should the expansion therefore be measured from ?
 
I'm a little unclear about the relevance of the movement relative to a "center of stiffness" at all. All the movements are equally relative to any fixed point - essentially it's a movement relative to a fixed frame of reference, not a point.

So why is the position of the center of stiffness relevant? If I picked a random point on the ground then would the numbers be any different?

I hope I covered this in my post above re the pinned beam and moving the pinned side, the direction of expansion is dependent on which end is stiffest.
The centre of stiffness is the stiffest point in the building
 
Video at 1:01:09
Hulsey: UAF ABAQUS Structural Expansive movements. I kind of want to share with you, this is the model we are talking about. This is Floor 13. This is the column 79 at floor 13, 1.85 inches to the right. That means east. It doesn't mean west.
So this whole thing moved. [...]
You can begin to see that the mov..., the displacements, if you start looking at -.5, now where is the zero at? It's over here somewhere [indicates a region with near-zero movement] So there's column 79 moving with respect to this over in this area. It's not moving with respect to this [indicates east side of building], it's not moving with respect to that [indicates west side]. It's moving this way and that way with respect to what we call the thermal centroid. Which is your stiffer[?] point. So basically you've got a center of stiffness by which this thing's behaving, and that's what's happening
Content from External Source
 
I hope I covered this in my post above re the pinned beam and moving the pinned side, the direction of expansion is dependent on which end is stiffest.
The centre of stiffness is the stiffest point in the building
Does it move?
 
I hope I covered this in my post above re the pinned beam and moving the pinned side, the direction of expansion is dependent on which end is stiffest.
so when Husley expanded the girder into column 79 he was going the wrong way?
 
More broadly, movement relative to a center of stiffness of the building is pretty much irrelevant when it comes to connection failure. It's the difference in motion between two connected parts (i.e. the relative motion) that leads to connection failure.
That is not the wisest thing you have ever said Mick. In essence you are trying to promote the idea that relative movement counts, but where the elements start from is not important. You should think about the above statement. It's telling.

I stand by it.

If the elements both move relative to some other point, but there is zero movement of the elements relative to each other, then how can the connection fail?
 
It depends on exactly what you are examining. The issue being discussed was if the girder walked off its seat. So the relevant movement is that of the girder relative to the seat.
How many times do I have to say this. In the ABAQUS model, UAF replicated NIST's model conditions and elements and got 5.1" movement in the girder relative to the seat.

More broadly, movement relative to a center of stiffness of the building is pretty much irrelevant when it comes to connection failure. It's the difference in motion between two connected parts (i.e. the relative motion) that leads to connection failure.
And you know this how exactly ?
You need to reference this claim. Frankly I think that's what you think, or wish was the case because it allows you to handwave the issue of the different approaches. Clearly we also need to see from UAF, an output for the movement relative to the seat, with the correct elements of course. Nobody's arguing about that as far as I know.
These are measures of different things. So do you agree they are not comparable, and that Hulsey has mistakenly presented them as if a direct comparison has meaning?
It should be clarified yes. I would like to think that if I was in the room, I would have asked that question. But it does not in any way invalidate the point that he made.
And are you saying that in reality there was no relative motion at any of the connections?
Again, how many times? Didn't say it. Never said it. Wouldn't say it.
What I will say is that we need to see that specific analysis to make the comparison, on that we agree.
 
I stand by it.

If the elements both move relative to some other point, but there is zero movement of the elements relative to each other, then how can the connection fail?
No. Just no.
What needs to be expressed is the difference. As I said, nobody is disagreeing with you there. Certainly not me.
 
On the whole, the point of comparison needs more explanation as far as the UAF project goes, but the difference in the 2 approaches is worth noting. Things do expand from their stiffest point. ie a beam pinned at one side will expand toward the other. Change the pinned side and it will expand in the opposite direction. Where should the expansion therefore be measured from ?

Expansion is a change in the length (practically speaking, ignoring non-axial expansion. It's the distance between the ends.

What's important is displacement of the ends, relative to what they are connected to.

And you know this how exactly ?
You need to reference this claim. Frankly I think that's what you think, or wish was the case because it allows you to handwave the issue of the different approaches. Clearly we also need to see from UAF, an output for the movement relative to the seat, with the correct elements of course. Nobody's arguing about that as far as I know.

I know it because it's blindly obvious. If a seat and its girder both move the same distance then that connection has not failed.

Only relative motion is important there.
 
so when Husley expanded the girder into column 79 he was going the wrong way?
No. I think you are talking about a different analysis there. The ABAQUS one.
And I have no doubt that the girder would expand hard up to the flange of column 79. I have maintained for quite some time that the girder would expand at least to the inside of the column side plate lip or overhang.
Here it is in a REuploaded video that our research team produced over 4 years ago


ADD hope you see how the animation illustrates the girder being trapped.
 
No. Just no.
What needs to be expressed is the difference. As I said, nobody is disagreeing with you there. Certainly not me.
Hulsey explicitly states there was no difference when talking about his SAP model.
Video 59:55
they moved together, they didn't move separately.
Content from External Source
 
I think you are talking about a different analysis there. The ABAQUS one.
nah, I don't know anything about NIST models.

ADD hope you see how the animation illustrates the girder being trapped.
I don't need a video to show me that if you expand the girder it would get trapped in the side plate. what I need is a video showing me Husleys timelapse fire model applied to the girder so I can see for myself if it actually expands far enough into column 79 at the right time to get trapped by the side plate.
 
Expansion is a change in the length (practically speaking, ignoring non-axial expansion. It's the distance between the ends.
Yes, but it's direction does depend on where the stiff point. You agree ?
What's important is displacement of the ends, relative to what they are connected to.
Obviously yes.
I know it because it's blindly obvious. If a seat and its girder both move the same distance then that connection has not failed.
Bingo. You got it.
Only relative motion is important there.
It's required yes. And quite a bit more than is possible at NIST's values and element choice.
 
nah, I don't know anything about NIST models.


I don't need a video to show me that if you expand the girder it would get trapped in the side plate. what I need is a video showing me Husleys timelapse fire model applied to the girder so I can see for myself if it actually expands far enough into column 79 at the right time to get trapped by the side plate.
The animations I linked you to show that this was worked out without a FEA. The UAF FEA confirms that we were correct.
I was talking about UAF's ABAQUS simulations.
Also there's a still shot of the relevant UAF analysis on page 43 of the PDF.
 
Hulsey explicitly states there was no difference when talking about his SAP model.
Video 59:55
they moved together, they didn't move separately.
Content from External Source
Well if that's what happened in the FEA, what would you have him say instead ?
It requires more analysis than is provided in the presentation, I will agree to that extent. but if they move together, then they move together.
What about "they moved separately, the same distance and direction" ?
 
I've never said anything different to this through the entire thread. So if someone just got something, it's not me.
Okay. If they move together does the connection fail ?
( i think you already said that wasn't the case, so I will presume) No

Did the UAF analysis show a failure in WTC 7 ?
I think we can safely say, NO.

What was the difference in the approach?

The composite nature of the floor system and steelwork, amongst other things.
 
Well if that's what happened in the FEA, what would you have him say instead ?
It requires more analysis than is provided in the presentation, I will agree to that extent. but if they move together, then they move together.

I would have him say:
"Our analysis shows that in no case did the end of any beam or girder move relative to the column or girder it was attached to. All girders, beams, concrete slabs, and columns acted as one composite object that simply expanded relatively smoothly about 12.5 inches from east to west. There were essentially zero local displacements, and so no connections, even seat bolts, could possibly have failed"​
Because that's what his results imply.
 
And are you saying that in reality there was no relative motion at any of the connections?
Again, how many times? Didn't say it. Never said it. Wouldn't say it.
Okay. If they move together does the connection fail ?
( i think you already said that wasn't the case, so I will presume) No

Did the UAF analysis show a failure in WTC 7 ?
I think we can safely say, NO.

What was the difference in the approach?

The composite nature of the floor system and steelwork, amongst other things.

So did Hulsey's study show that the south end of A2001 moved relative to the seat at C79, or not?
 
So did Hulsey's study show that the south end of A2001 moved relative to the seat at C79, or not?

The one where they tried to replicate NIST did yes. 5.1" to the West in the girder.
The other analysis showed that "they move together" when a composite nature of the floor system is considered.

What analysis would you like to see ? Seriously.
I would imagine a small scale ABAQUS analysis specific to these elements that accounts only for the NE corner maybe ?
 
The other analysis showed that "they move together" when a composite nature of the floor system is considered.
So you think that's accurate? All connections move together? Smooth expansion of the entire floor system? Zero possibility for connection failure. Flanges and side plates not even slightly relevant?
Floor 13 ABAQUS displacement map.jpg

Or do you think there's a slight possibility that Dr. Hulsey made his students make the floor system a bit too composite?
 
So you think that's accurate? All connections move together? Smooth expansion of the entire floor system? Zero possibility for connection failure. Flanges and side plates not even slightly relevant?
Floor 13 ABAQUS displacement map.jpg

Or do you think there's a slight possibility that Dr. Hulsey made his students make the floor system a bit too composite?
No, They tried different levels of friction. He says that in the presentation. From none to full.
You're struggling here and making insinuations about "a slight possibility", you should have more respect for the man's integrity, even if you don't like what he is telling you.
 
The animations I linked you to show that this was worked out without a FEA.
I don't see your work either ( I only watched for 5 minutes then got bored)

The UAF FEA confirms that we were correct
the UAF did not model the actual fire though, as far as anyone knows.

I don't want to have this conversation again, or interrupt your current discussion further.
 
I don't see your work either


the UAF did not model the actual fire though, as far as anyone knows.

I don't want to have this conversation again, or interrupt your current discussion further.

this is just wrong from start to finish. Advice would be to wipe it along with this comment.
 
No, They tried different levels of friction. He says that in the presentation. From none to full.
You're struggling here and making insinuations about "a slight possibility", you should have more respect for the man's integrity, even if you don't like what he is telling you.

Alright, I'll explicitly state that his result of zero local displacements looks like nonsense to me, and I think his floor models are unrealistically constructed and heated. You seem to accept it as "that's what happened in the FEA", and out of respect for his experience and integrity.

You spent years arguing that the girder did not move enough relative to the column. Are you now going to say you think it didn't move at all relative to the column?

It's not a problem that different models (and different parameters) give different results. The problem here is that Hulsey explicitly presented this zero relative movement as an actual end result of his study. He also makes a comparison of 5.5" vs. a meaningless 2" (which should have been 0").
20170917-111319-98s7w.jpg

I have brought this up with him as best I can. I have emailed him asking about, and I added a comment to the YouTube video (comment is waiting approval).

Perhaps you could ask him for clarification.
 
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