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Old 3rd June 2016, 01:25 PM   #81
tfk
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Originally Posted by Spanx View Post
I'm no expert on these things.

If the H beams had brackets welded on all four sides (both ends) would we expect to see them deform in the same way as the crushed columns you have shown.
Every detail affects the results, including end constraints.

Please don't misinterpret what I've written. I did a lousy job of explaining the papers to which I was referring.

First was the paper cited here. “Reassessing the Plastic Hinge Model for Energy Dissipation of Axially Loaded Columns”

The “"Reassessing the Plastic Hinge Model” paper claimed to obtain "more accurate" values for the amount of energy absorbed by buckling than Bazant used in his first (“Simple Analysis”) paper. It claims that Bazant’s value for “most optimistic for collapse halt” is not really a “worst case condition. That there are conditions in which some columns might absorb more energy in crushing than Bazant calculated.

If you are trying to get “most optimistic condition for collapse arrest”, then it appropriate to use “single column buckling” as your failure mode, as Bazant did.

If you are trying to get “likely, real energy absorption in the real collapse”, then it is either intentionally deceptive or incompetent to use "single columns buckling” as your failure mode, because that is not how they failed.

The buckling failure modes shown in Korol's paper absorb way, way too much energy. Because that is NOT how the columns failed. There were zero columns in the debris pile that folded in this manner.

It is deceptive to use column buckling at all, because that is not how they failed.

The failure mode was "bolts & welds snapping".
__

The paper that I was addressing, with the images of crushed square tubes, was a different one of Korol’s, “Collapse Time Analysis of Multi-Story Structural Steel Buildings”,
by Robert M. Korol,*, K.S. Sivakumaran and Frank R. Greening

The failure mode that I showed in those images is virtually impossible to achieve in any real collapse. There is no way that any WTC column failed this way.

The “Collapse Time Analysis” paper made some absurd assumptions about failure modes, including:

Originally Posted by Korol, et al
Tubular Steel Columns
As presented later, the sample building considered in this paper utilizes square columns, for which the slenderness parameter was computed to be at the very low end of the cut-off value for short to intermediate length columns [13] and hence such compression members could qualify as short columns, prone to axial crushing. As such an analysis based on tubular crushing may be appropriate when the tubular dimensions and effective lengths warrant it. Research done by Wierzbicki and Abramowicz [8] and later by Abramowicz and Jones [17] on both quasi-static and dynamic crushing of tubular members, is deemed to have relevance in estimating the energy dissipation of such columns during a story collapse event. From their analytical and experimental study, a formula was developed by Wierzbicki and Abramowicz [8] for the average crushing resistance, Pm, during which progressive stages of plate element folding, compressing, and sequential propagation occurred, until the member became totally squashed.
This is an absurd assumption for energy absorption during the collapse of the towers.

This is what I was addressing with those images.
My fault for failing to make that clear.
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Old 3rd June 2016, 01:49 PM   #82
Spanx
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Hi tfk,

I am looking at the experiment with no Truther dressing applied.

I'm curious how the H beams would deform if they had brackets or were braced at the top or bottom.
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Old 3rd June 2016, 03:13 PM   #83
ProBonoShill
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Originally Posted by GlennB View Post
I'd say that "Been used in the real world" is quite a stretch. "Been used in futile debate about 9/11 CT" would be more like it.
Exactly. Thank you.
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Old 3rd June 2016, 03:57 PM   #84
ozeco41
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Originally Posted by Spanx View Post
Oz

I will except any Truther peer reviewed paper that anyone has benefitted from.
Thanks for the clarification.

It's not a paper but one of the first truther sources that helped me was an early video by David Chandler. Circa 2008. It was intended by DC to illustrate "squibs" cutting floor joists in the Twin Towers progression stage. So he focussed on that aspect - what we would call "dust spurts" ejected several floor levels below the visible collapse front.

BUT - unnoticed or at least not commented on by D Chandler his video showed several other key features of the real collapse progression mechanism. I had already described it on that forum. And it was before the somewhat contentious acronym "ROOSD" became known.

Another truther graphic source is this static clip from a motion gif by Achimspok. He is or was a long term committed truther who did a lot of good research following his areas of interest.

The arrows and coloured lines are my additions. I must have used it dozens of times across several forums - it explains how "initiation' changed to "progression". My emphasis was on why the columns did not impact axially - which is a contentious issue for many members on "both sides".

So two more "beneficial" uses of truther material - but neither of them "peer reviewed papers".

Originally Posted by Spanx View Post
So far it would appear to be you, Tony Sz, and debunkers who have benefitted from them.
Yes - so far. Those are only the examples I remember "top of my head". Other members may have more.

Originally Posted by Spanx View Post
I'm not sure if I come in the debunker category? I don't think I have benefitted from them.
Sure. "debunker" is too limiting a class. The polarisation "truthers" v "debunkers" is only a few years old - and causes problems. It is a built in false dichotomy. Too "black or white". It prents many like me with difficulties from being identified as "one side or the other" in situations where both sides are wrong.
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Old 3rd June 2016, 10:43 PM   #85
Spanx
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Oz

I spent a fair amount of time following the thermite discussion. Outside of that discussion, the place I call the "real world" I can honestly say I have not benefitted from it in any way shape or form and can't see how anyone has. Perhaps a thermite testing kit will be on the shelves soon, which could come in handy while entering buildings.

I can just see it now. The Neils Harrit thermite testing kit, "don't leave home without it" all proceeds go to AE911 truth.


Maybe these Truther peer reviewed papers have benefitted you in what you call the "real world" they haven't for me.


I think GlennB hit the nail on the head with his comment.

Last edited by Spanx; 3rd June 2016 at 11:33 PM.
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Old 3rd June 2016, 11:41 PM   #86
ozeco41
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Originally Posted by Spanx View Post
Oz

I spent a fair amount of time following the thermite discussion. Outside of that discussion, the place I call the "real world" I can honestly say I have not benefitted from it in any way shape or form and can't see how anyone has. Perhaps a thermite testing kit will be on the shelves soon, which could come in handy while entering buildings.
Thanks for the comments. I respect and understand your position but the difference of perspective between us on reasoned discussion is almost certainly unresolvable.

The comments which Oystein, Georgio and I make may just as well be in Hindustani - they fall outside your approach to reasoning.

There is no value in me trying once again to explain the issues of concern. Even with positive intent by all parties those responding will inevitably divide into those - like you and several others differing on what the issue of concern is whilst Oystein. Georgio and I can repeat endlessly that the concern is procedural and definitional. We are talking about different things.

Despite my better judgement let me refer to just one more point.

You have just said that the "real world" for you is every thing outside discussion of thermXte. I doubt that you meant that or realised the effect of what you said. BUT if you do mean it you have just agreed that every point I have made is in the "real world" because I have not given one example which is contained within the discussion of "thermXte".

Gawd - here is another one:
Originally Posted by Spanx View Post
Maybe these Truther peer reviewed papers have benefitted you in what you call the "real world" they haven't for me.
You have just defined what is "real world" for you. And all my comments are outside "thermXte" debate and therefore inside YOUR real world as you defined it in your previous paragraph.

Can you see why Oystein, me and Georgio raise questions? If not let's discontinue the discussion - as I suspect the other two already have. People were getting angry because THEY did not understand other peoples posts and were blaming the other party. Mostly Oystein. I understood all of Oystein's questions - and agreed with many of them.

So lets withdraw from the confrontation. I will. Your thread - and I cannot contribute on the basis that you and others prefer.

One last comment:

Originally Posted by Spanx View Post
I think GlennB hit the nail on the head with his comment.
So do I - he hit the issue of fact precisely and it is a legitimate point of view - on that issue of fact and from his perspective.

BUT it was not your OP - he set his own criterion and applied his own judgement. Confirming the two key points I have made several times. And I'll bet he doesn't see that he was agreeing with me.

And his post follows EXACTLY the process that I used in my last couple of posts trying to meet your requirements.

And I'll bet that those last several comments "don't compute" for you. So I'll depart the thread.

My sincere best wishes for you and other members.
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Old 3rd June 2016, 11:57 PM   #87
Spanx
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Oz

I will be honest with you here. I haven't read all of you last post because you ramble on.

If your idea of the real world is different to mine so be it. If you can't see the difference between Truther papers and no Truther paper so be it. If Oystein and Georgio can't so be it.

If Oystein want to start insulting, that's his problem.

I wait for your very long winded post with pretty yellow bits. (Which I probably won't read)

Keep enjoying the benefits you feel you have gained from Truther peer reviewed papers.
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Old 4th June 2016, 12:10 AM   #88
ozeco41
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Originally Posted by Spanx View Post
Oz

I will be honest with you here. I haven't read all of you last post because you ramble on.

If your idea of the real world is different to mine so be it. If you can't see the difference between Truther papers and no Truther paper so be it. If Oystein and Georgio can't so be it.

If Oystein want to start insulting, that's his problem.

I wait for your very long winded post with pretty yellow bits. (Which I probably won't read)

Keep enjoying the benefits you feel you have gained from Truther peer reviewed papers.
I'm sorry that you need to resort to lies and insults and blaming others for your own lack of understanding.

The thread shows that I have tried but my patience is exhausted.

CUL8R

Last edited by ozeco41; 4th June 2016 at 12:18 AM.
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Old 4th June 2016, 12:22 AM   #89
Spanx
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I apologise if you found my post insulting although I am not sure which bit you found insulting.

And I will think about who I am blaming.
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