OOS Collapse Propagation Model

[JSanderO]

I don't like cross forum posting, but this is for you JSO.

https://www.physforum.com/index.php?showtopic=12383&st=120


The spire is where I first noticed the oscillations, thanks for pointing them out.
The building is an interdependent structure relying on the unity of the connected parts for strength a constantly building Oscillation destroys that unity, by allowing the components to act independently of the Structure.
Destroy the unity of the structure and it collapses like a house of cards.
In fact the only way the buildings can collapse, is though the destruction of the buildings unified strength!
The company in Japan that made the beams might have the data your looking for if they still exist, and no their were no reinforcing plates needed.
The Beams were made to be continuously welded, all that is needed is a tapered structure to the beam to allow access to the other side.
Constantly overlaying the weld onto the material while maintaining a constant temperature of the weld allows for and even and constant weld by keeping the welded part in a plastic liquefied state.
The you simply v out the section to be welded and keep the temperature constant using a Torch to control the temperature of the beam and weld, by the color produced though heating.
It is much harder to weld high carbon tool steels than low carbon structural steels
and I weld tool steel using the process all the time.



This post has been edited by Chainsaw, on Feb 8 2007, 02:16 PM

I ment columns but put beams, didn't have much time to post back then constantly working
And on the road. Always in a rush.

The Spire columns likely oscillated as you call it. Some actually swayed in the wind. It's my understanding that since the columns were multi-part stacks thew Euler buckling forces caused them to self buckle which I suspect did not cause them to part at the base but more likely close to mid height or higher. They were tapered so the splices and the sections were smaller going up. When a single slender column buckles it does so at its mid point. You can see this if you take a thin piece of wood and press down... it bows out in the middle then snaps in the middle.

NB there were a few 2 and 3 section bits in the debris pile. These sections were from the bottom of the multi part stack of core columns.

 

[Crazy Chainsaw]

The Spire columns likely oscillated as you call it. Some actually swayed in the wind. It's my understanding that since the columns were multi-part stacks thew Euler buckling forces caused them to self buckle which I suspect did not cause them to part at the base but more likely close to mid height or higher. They were tapered so the splices and the sections were smaller going up. When a single slender column buckles it does so at its mid point. You can see this if you take a thin piece of wood and press down... it bows out in the middle then snaps in the middle.

NB there were a few 2 and 3 section bits in the debris pile. These sections were from the bottom of the multi part stack of core columns.

The Ossilations would have broken the welds JSO, that's why there is evidence of the phenomenon of sheer lag in the columns, buckling alone would have caused bending,
and more ductile deformation.

I agree though they separated at the welds in the middle of the columns.

 

[Crazy Chainsaw]

Yes - subject to the second criteria I've posted several times - the need to check sensitivity to gross changes in mechanism - to ensure the we are not seeing "right results for wrong reasons" which is one of those hard to detect insidious errors in engineering modelling and other aspects of applied science. My position still the same on that one. I cannot prove it is but it is up to those who make the claims to satisfy the validity of their assumptions - I would need to see that factor legitimately addressed rather than rely on mere authority of the postulating academics - if in fact they even recognise the issue.

Thank you for that bit. And - yes - I agree it could well be several other energetics - exactly the point I made recently in suggesting how the Bazant desire to develop a generic 1D model may be chasing an unattainable goal BUT could possibly be made valid across the range of column spacings IF the energetics factor in the maths could accommodate the variations.

A good start and heading in the right direction. There is an aspect of scope I will try to address once I get my head clear of the fog caused by all the noisy stuff on the thread. I don't want to risk making errors given that you are addressing the level of argument I can appreciate and respect.

Agreed with the same reservation about the "scope" issue I want to address.

Correct as far as it goes. But bear in mind that validation is not limited to maths though that is the most likely path. It could be by explanation of mechanism with less rigorous maths. We wont know till someone goes there. So I'm staying with the "Engineering Managers Position" - the basis on which I could l stake my professional reputation when assuring an astute client - for a billion or multi billion dollar project. I cannot rely on it without the assumptions being shown to be valid to a professionally supportable level.

Your point "If no one has done this work, then it is impossible to say if it is a valid or invalid approximation." supports what I say - I take the next step - I'm not accepting it as valid without proof. If strict proof is not possible I would look for a risk managed probabilities based assessment. Which takes us up one level further in the sophistication. BUT it can be sufficiently persuasive of validity IF someone does it. I don't limit the methods - merely identifying the need to see it done and done persuasively.


The same key point as previous. Already explained.

Thanks Bravin - you are hitting the issues at the level I respect - put simply "We are near enough on the same sheet of music".
[qimg]http://conleys.com.au/smilies/clap.gif[/qimg]

How many in this discussion didn't read, WTCREPORT. PDF?
ENERGY TRANSFER IN THE WTC COLLAPSE,
By Dr. Frank Greening.

 

[Major_Tom]

Yes Major Tom we all know, if you check my posting history on all the forums you will note I quit posting when it was clear, that David Benson, was going to use the crush down, crush up model which I knew was wrong before BLGB was published.

Yet you subscribe your meme falsely to me!

No, not to you. And you are smart to distance yourself from the others here who are still following that white rabbit.

Do you even have a clue what would have shielded the core and allowed the spire to form?

There was no 'spire'. That is an old meme. The entire east-west width of the core remnant survived the initial collapse. The WTC1 core remnant was correctly mapped for the first time in 2009. See the first point in this link:

Progressive Floor Collapses in the WTC Towers

How many in this discussion didn't read, WTCREPORT. PDF?
ENERGY TRANSFER IN THE WTC COLLAPSE,
By Dr. Frank Greening.

I did. Because it uses energy transfer rather than roofline and crush front mapping, it is a much better paper than BL and BLGB.

 

[JSanderO]

No, not to you. And you are smart to distance yourself from the others here who are still following that white rabbit.

There was no 'spire'. That is an old meme. The entire east-west width of the core remnant survived the initial collapse. The WTC1 core remnant was correctly mapped for the first time in 2009. See the first point in this link:

Progressive Floor Collapses in the WTC Towers

I did. Because it uses energy transfer rather than roofline and crush front mapping, it is a much better paper than BL and BLGB.

The "spire" is a term of art and refers (my understanding) the collection of columns which remained for a period after the floors collapsed and the facade had peeled away. The tallest column I believe was 501 which stood to about flr 72 or so... and I suppose people think of this columns a "the" spire.

 

[GlennB]

The "spire" is a term of art and refers (my understanding) the collection of columns which remained for a period after the floors collapsed and the facade had peeled away. The tallest column I believe was 501 which stood to about flr 72 or so... and I suppose people think of this columns a "the" spire.

And some perspectives heightened the impression of a "spire":



More chest-beating about his "mappings" from M_T. Nothing to see here ....

 

[beachnut]

The no spire meme missed by the major enemy of NIST and Bazant... was the gravity collapse really an illusion? To who?

lol, what we have here is a failure to understand models, engineering, and science, with a dash of no math...

Happy monday...

 

[Crazy Chainsaw]

No, not to you. And you are smart to distance yourself from the others here who are still following that white rabbit.



There was no 'spire'. That is an old meme. The entire east-west width of the core remnant survived the initial collapse. The WTC1 core remnant was correctly mapped for the first time in 2009. See the first point in this link:

Progressive Floor Collapses in the WTC Towers






I did. Because it uses energy transfer rather than roofline and crush front mapping, it is a much better paper than BL and BLGB.

Yes the core remnant did survive, that is why ossilations were a factor.
Individually if ossilations affected columns, they would simply have collapse not ossilated.

Yes BLGB, was mainly to debunk the book by Gordon Ross and do falsify claims in the physics community.

It is a physics model of the collapses, not a specific engineering model.

The Greening paper is much better, but was in dispute at the time by Gordon Ross and other Cters.

 

[Crazy Chainsaw]

And some perspectives heightened the impression of a "spire":

[qimg]http://i250.photobucket.com/albums/gg274/sap-guy/spire_zpspbewyybe.jpg[/qimg]

More chest-beating about his "mappings" from M_T. Nothing to see here ....

That GlennB is a little further in the collapse after the bracing welds begin to fail, do to ossilatory damage.

A simple matter of time, between images.

 

[GlennB]

That GlennB is a little further in the collapse after the bracing welds begin to fail, do to ossilatory damage.

A simple matter of time, between images.

Quite possibly, but it shows that whining about "there was no spire ... I have mappings" is just meaningless hot air.

 

[Crazy Chainsaw]

Quite possibly, but it shows that whining about "there was no spire ... I have mappings" is just meaningless hot air.

It relates to collapse front progression, a small section of the core remained after the collapse front passed, however the bracing was not actually intact, it was damaged by the same forces that protected that section, and collapsed via it's own weight shortly after collapse progression.

 

[Major_Tom]

It relates to collapse front progression, a small section of the core remained after the collapse front passed...

Not a small section. The entire east-west length of the core remained temporarily.

Check out video linked here to see highest columns falling on the east side.


It was a 'double-spired cathedral'. The tallest portion of the east side was as tall as the tallest portion of the west side. They are visible in the videos to which I linked earlier.

As the tallest portion of the east side fell eastward, the hinge portion can be seen hitting the west side columns within those videos.

>>>>>>>>>>

Quite possibly, but it shows that whining about "there was no spire ... I have mappings" is just meaningless hot air.

Your emotions are once again clouding your ability to reason. Very unhealthy.

 

[GlennB]

Not a small section. The entire east-west length of the core remained temporarily.

[qimg]http://femr2.ucoz.com/_ph/6/2/665519550.gif?1443554820[/qimg]

[qimg]http://femr2.ucoz.com/_ph/6/2/697379613.jpg?1443554893[/qimg]

It was a 'double-spired cathedral'. The tallest portion of the east side was as tall as the tallest portion of the west side.

As the tallest portion of the east side fell eastward, the hinge portion can be seen hitting the west side columns within the videos to which I gave you a link previously.

So what? This is an easier illustration (p.s. why do your posts always appear with multiple blank lines? Sometimes several between paragraphs? Just interested)

 

[Oystein]

Thanks for admitting that.

[...that I, Oy, haven't read BV or BL and am not interested]

There is no logical reason to express strong views of any kind over a paper you have not read.
...

Can you please be clear:
Do you claim that I, Oystein, have expressed strong views of any kind over BV and/or BL?

 

[JSanderO]

There were 47 core columns and clearly rows 500 and 600 and some of 700 were part of the surviving "spire... that's close to half and I am uncertain of any from rows 800, 900 and 1000.

Several of the columns in rows 500 and 600 were connected by horizontal steel which might have been to support the elevator rails or may be bracing... Not likely the belt girder... that went down with the floor collapse.

 

[Oystein]

Really? Pray tell, what did I rest on BV, on what occasion?

This should be interesting...

Wait - do you mean ... we might have a case of "lie by innuendo" at hand??

 

[Oystein]

No.

If you are not prepared to address my reasoning ...

The problem really is that you completely and utterly fail to address MY reasoning. I think you don't understand at all what I have been writing; you seem to be entirely blind to my arguments. I have no better explanation for why you so egregiously misstated my argument.

Alternatively, you might have lied. But I have complete trust that you don't.

Last time I checked the relevant posts in the thread both you and Myriad were discussing the BV paper

Nothing could be further from the truth.
I told you explicitly that I am neither interested nor able to discuss the BV paper for I never really read it. See, you absolutely, completely, misread, misunderstand, misrepresent what I have been discussing.

Try again - please!

 

[beachnut]

...
There was no 'spire'. ...

Not a small section. The entire east-west length of the core remained temporarily....

Your emotions are once again clouding your ability to reason. Very unhealthy.

What is the extra BS at the end. Plus it was a small section, the spire is very small; oh you are saying below the spire there is more core which is failing... What it the emotions stuff? You said no spire, there is one; then you spew more BS showing us all what is in the record which everyone has access to.

Oops, now there is a spire... oops, you are letting your ego hide the fact the top section is small, like ignoring reality there is a small part... quibbling about BS; for study with no purpose.

Does this mean the gravity collapse is an illusion?

These are just some of the factors which, when studied in depth, show that the supposed "gravity-driven collapse" is a mere illusion to mask an intentional act so barbaric, so inhumane and morally impoverished that the fabled characteristics of Satan come to mind. ....

Are those facts in your book? This is your history, on the Internet.
Is the gravity collapse and illusion, or not? You book only makes fun of science and models.

This is your history, the record, I have collected it, as has the Internet...
Have you dropped the fantasy of CD; if so, how did you overcome you illusion BS, when and why?

 

[Crazy Chainsaw]

Not a small section. The entire east-west length of the core remained temporarily.

[qimg]http://femr2.ucoz.com/_ph/6/2/665519550.gif?1443554820[/qimg]


[qimg]http://femr2.ucoz.com/_ph/6/2/697379613.jpg?1443554893[/qimg]


[qimg]http://www.sharpprintinginc.com/911/images/photoalbum/13/sullivanjr03z.jpg[/qimg]


Check out video linked here to see highest columns falling on the east side.


It was a 'double-spired cathedral'. The tallest portion of the east side was as tall as the tallest portion of the west side. They are visible in the videos to which I linked earlier.

As the tallest portion of the east side fell eastward, the hinge portion can be seen hitting the west side columns within those videos.

>>>>>>>>>>





Your emotions are once again clouding your ability to reason. Very unhealthy.

I am referring to the parts with intact or seemingly intact bracing, not the columns themselves that towered above it, when I say small portions.
The parts with bracing are smaller in height than the columns.

 

[JSanderO]

What is this stupid dispute about... were there columns which survived the floor collapse?

Yes

How many?

hard to tell looks like the north side of the core.. at LEAST you can see 2 rows because the are connected with steel beams


And col 501 is 72 or so stories tall with no bracing (obviously) where it towers above the rest of the surviving core. 501 was one of the 4 strongest column in the building.