OOS Collapse Propagation Model

[ozeco41]

Ozzie,

I have always thought that the understanding of the collapses of those buildings would HAVE to involve the nature and perhaps details of the particular structures. How could it not?

That is the single issue at the core of these ongoing connections and confusions.

Yes it is my difference with Crazy Chainsaw over Benson. Benson is not describing the real WTC collapse whether he thinks he is or not.

Progression at WTC Twins was by a method which has been labelled "ROOSD" - whether or not people like the name the mechanism is what happened. It was NOT column crushing as per the B&Z "Limit Case" paper."

So anyone - truther or debunker or you or me or Major _Tom will be WRONG if they
A) apply column crushing dynamics to the WTC real event collapses.

UNLESS

B) they demonstrate that a 1D homogeneous model can validly approximate the real event.

"A)" is the biggest source of unintended confusion OR half truth mendacity in these discussions WHILST "B)" is the only valid cop out I can identify. And AFAIK no one has validated the approximation.

I continue to try to ignore the foggy overlay of "He tells more lies than we do" etc. The two way personal sniping adds nothing to progressing the discussion or clearing confusions.

Do you think those questions have been answered?

YES...but...
Few of the explanations are clear concise and complete; AND
The ever present belief that published words by academics which are or may be partially wrong outweigh soundly reasoned arguments by professionals such as me which are merely posted on forums without the trappings of peer review.

Wow. If they are wrong they are wrong.

If I or you or we are right - I/you/we are right.

..and I would welcome any rational reasoned efforts to prove me wrong. I enjoy the challenge to improve my own understanding

 

[Crazy Chainsaw]

What IS the mass shed? How do you know how much mass was "shed"? Are you referring to the ejecta seen shooting out the windows during collapse?

Why do you think this is a significant amount (or not) to alter the collapse?

The shed mass is any mass, that does not contribute to crushing up or down, anything ejected, or converted to gasious form steam, given off by heating, or carbon dioxide from the combustion of carbon, SO2, from combustion of sulfur, anything that would have been in the buildings when they collapsed and escaped before final impact.

You have to know the structural resistance, and the speed of the collapses, then you can estimate it on that.

All the energy of crushing is gravitational potential, converted into Kinetic energy.

If I have 2 times the resistance to crushing, the crush occurs that much slower.
If I have a 1/4 the resistance to crushing the crush by an equal amount should be faster.

 

[JSanderO]

The shed mass is any mass, that does not contribute to crushing up or down, anything ejected, or converted to gasious form steam, given off by heating, or carbon dioxide from the combustion of carbon, SO2, from combustion of sulfur, anything that would have been in the buildings when they collapsed and escaped before final impact.

You have to know the structural resistance, and the speed of the collapses, then you can estimate it on that.

All the energy of crushing is gravitational potential, converted into Kinetic energy.

If I have 2 times the resistance to crushing, the crush occurs that much slower.
If I have a 1/4 the resistance to crushing the crush by an equal amount should be faster.

Roger that... but in the case of the twin towers I suspect and can't prove and you can disprove that the mass shed had negligible effect on the floor destruction / ROOSD process. A fair amount of superimposed loads (mass) contents of the floors and some walls were blasted out of the windows and did not aid in ROOSD.

ROOSD doesn't need the superimposed loads... the slabs are more than enough I suspect to do ROOSD.

Mass shedding is a red herring and a blue crab.

 

[Crazy Chainsaw]

Yes it is my difference with Crazy Chainsaw over Benson. Benson is not describing the real WTC collapse whether he thinks he is or not.

I never said that he was in the paper he gives a 2D, example of the physics of building collapse based on the physics of three energy sources.

Gravity,
Structural resistance,
Air resistance.

Progression at WTC Twins was by a method which has been labelled "ROOSD" - whether or not people like the name the mechanism is what happened. It was NOT column crushing as per the B&Z "Limit Case" paper."

Yes but.both Column Crushing and ROOSD will exhibit similar though distinct behaviors that can be compared,, such as mass shedding, and resistance to crushing.

I am not saying that column crushing is what happened, I am saying that a model
Of column crushing, can be compared to a model of ROOSD, on the simplified basis of potential energy and resistance to crush, when the same static load is converted to dynamic
Loading.

So anyone - truther or debunker or you or me or Major _Tom will be WRONG if they
A) apply column crushing dynamics to the WTC real event collapses.

Absolutely, and I am not doing that, I am comparing model A with model B, in a simplified dynamic.

UNLESS

B) they demonstrate that a 1D homogeneous model can validly approximate the real event.

The model doesn't have to it only needs to show that structural resistance of model A exceeds model B. Then compare the results hypothetically to the real event.

If I have a car that goes 250 mph, and I have one that goes 25 miles in hour, it is not hard
to know which car to inter into a car race.

"A)" is the biggest source of unintended confusion OR half truth mendacity in these discussions WHILST "B)" is the only valid cop out I can identify. And AFAIK no one has validated the approximation.

I continue to try to ignore the foggy overlay of "He tells more lies than we do" etc. The two way personal sniping adds nothing to progressing the discussion or clearing confusions.

YES...but...
Few of the explanations are clear concise and complete; AND
The ever present belief that published words by academics which are or may be partially wrong outweigh soundly reasoned arguments by professionals such as me which are merely posted on forums without the trappings of peer review.

Wow. If they are wrong they are wrong.

If I or you or we are right - I/you/we are right.

..and I would welcome any rational reasoned efforts to prove me wrong. I enjoy the challenge to improve my own understanding

Totally agreement.

 

[Crazy Chainsaw]

Roger that... but in the case of the twin towers I suspect and can't prove and you can disprove that the mass shed had negligible effect on the floor destruction / ROOSD process. A fair amount of superimposed loads (mass) contents of the floors and some walls were blasted out of the windows and did not aid in ROOSD.

ROOSD doesn't need the superimposed loads... the slabs are more than enough I suspect to do ROOSD.

Mass shedding is a red herring and a blue crab.

Even in ROOSD the buildings will exhibit both gravitational potentially, and structural resistance to loading, those are key factors of any building even in collapse.

 

[ozeco41]

Yes it is my difference with Crazy Chainsaw over Benson. Benson is not describing the real WTC collapse whether he thinks he is or not.

I never said that he was in the paper he gives a 2D, example of the physics of building collapse based on the physics of three energy sources..

A very positive and carefully presented post Crazy Chainsaw. Let me respond in detail.

This first comment shows that we are agreed that Benson was not referring to the real event collapse. There is no need for me to address the remainder of your comment - at this stage - I'll take the "rain check" on that part.

Progression at WTC Twins was by a method which has been labelled "ROOSD" - whether or not people like the name the mechanism is what happened. It was NOT column crushing as per the B&Z "Limit Case" paper."

Yes but.both Column Crushing and ROOSD will exhibit similar though distinct behaviors that can be compared,, such as mass shedding, and resistance to crushing.

Again we agree on my key point - the two mechanisms are different. Yes they can be validly compared - but that is not relevant to my claims OR the current status of THIS discussion. So another issue on which I'll take a "rain check".

Score: Two key points of agreement so far.

...I am not saying that column crushing is what happened, I am saying that a model Of column crushing, can be compared to a model of ROOSD, on the simplified basis of potential energy and resistance to crush, when the same static load is converted to dynamic Loading.

Two points there and we agree fully with the first - "column crushing is [NOT] what happened". I agree the second claim about comparisons provided the comparison is validly structured. And that is the second main point I've been repeating for several years. Specifically as far back as 2010 and possibly earlier I suggested that the maths supporting the column crushing explanations could be adjusted to validly approximate the real event if the column crushing energetics parts of the formulas were replaced by "floor joist shearing energetics".

Count that as 1.5 points of agreement. Or 0.5 new point and that could be 1.0 if you agree to my position.

Score : 2.5 Key points of agreement. With 0.5 in limbo

So anyone - truther or debunker or you or me or Major _Tom will be WRONG if they
A) apply column crushing dynamics to the WTC real event collapses.

Absolutely, and I am not doing that, I am comparing model A with model B, in a simplified dynamic.

Another point we agree on. And I'm aware of what you are doing but it does not progress the discussion. So yet another "rain check" on a sideline issue.
Score 3.5 key points of agreement.

The model doesn't have to it only needs to show that structural resistance of model A exceeds model B. Then compare the results hypothetically to the real event.

The model doesn't have to it only needs to show that structural resistance of model A exceeds model B. Then compare the results hypothetically to the real event.

If that is your purpose that is true. It isn't true for what I have been discussing. You have now completely "changed horses in mid stream" (AKA "shifted the goalposts".) I have no objection to discussing your different objective - but NOT now in the midst of a different discussion when you are responding to my assertions out of context and force fitting your own context.

Zero extra points.

If I have a car that goes 250 mph, and I have one that goes 25 miles in hour, it is not hard to know which car to inter into a car race.

Don't "lead with your chin" with a false analogy. If I have a real car that can do 25mph and you have a plan of a fantasy car that can do 250mph - guess which one I would back in a race.

"A)" is the biggest source of unintended confusion OR half truth mendacity in these discussions WHILST "B)" is the only valid cop out I can identify. And AFAIK no one has validated the approximation.

I continue to try to ignore the foggy overlay of "He tells more lies than we do" etc. The two way personal sniping adds nothing to progressing the discussion or clearing confusions.

YES...but...
Few of the explanations are clear concise and complete; AND
The ever present belief that published words by academics which are or may be partially wrong outweigh soundly reasoned arguments by professionals such as me which are merely posted on forums without the trappings of peer review.

Wow. If they are wrong they are wrong.

If I or you or we are right - I/you/we are right.

..and I would welcome any rational reasoned efforts to prove me wrong. I enjoy the challenge to improve my own understanding

Totally agreement.

Great. And thanks for your input.

Score 4.5 key points of agreement. Out of 5 points that are key to my claims so that is 90% agreement with the last 10% awaiting your call. And with that last issue - my position is a subset of yours so it should be OK.

That makes you and me and most of Sander in agreement on several of the key issues.

Let's go and convert the heathen, the fence sitters and those unwilling to commit.

 

[Major_Tom]

Something that he acknowledged a few posts later - a slip, and nothing to do with the substance of the discussion. He was writing about B+Z, as you well know from the exchange at the time, as did he.

Once again, if you could understand what he was saying you'd be able to see how screwed up his comments are.

Link to his comments:

R Mackey comments




After screwing up on the quote you cited, he writes;

It's much worse than that. Bazant and Le Zhou was written within 48 HOURS of the incident.

I talked about this in my discussions on Hardfire. Basically, Bazant and Le Zhou present a simplified model to illustrate certain features and phenomena relative to the actual events. The Truthers, casting about in desperation for a windmill to tilt at, seize not upon the phenomena nor on providing an alternate conclusion, but instead bitch about the model.

We know the model isn't precise. That's the whole point.

It's like watching reviewers in another country critique Shakespeare despite not understanding the language, going off what they get from the Google translator. The Truthers simply do not understand what they're talking about, and wind up criticising their own misapprehensions. That, plus being totally ignorant of the many other journal papers on the subject. Is it any wonder there's no point talking to them?

I also don't think the simple model is a perfect representation of reality. In fact, going back to Hardfire, I presented my own model (a cartoon, really, but it could be expanded on) of the collapse initiation and progression. It's in these slides. Reading this, the Truthers will probably crow that I've "refuted" or I "discount" Dr. Bazant, but of course that's not true at all.

He simply put a line through the word "Le" and wrote "Zhao", and then continued talking about the wrong paper completely oblivious to the fact that he was talking about the wrong paper.


After the meaningless lecture on the wrong paper, he writes:

Oops. You are correct. Fixing now...

Too many acronyms!

ETA: I wonder what Major_Tom meant by "BL" then? There is no relevant article with only Dr. Bazant and Jia-Liang Le. I just assumed he meant Bazant & Zhou.

Meaning he never knew the paper existed until I mentioned it, and therefore never even read it. But such a small detail still doesn't keep him from continuing to lecture on it. But how does one do that if they never read the paper? Well, within this environment all you have to do is give the pre-processed memes he had already given on the wrong paper, written with an entirely different argument 6 years before the paper in question. After all, in this brain-dead environment the peanut gallery won't know the difference anyway.




His next post shows he still doesn't know which paper he is talking about:

Seeing as how there is no paper by Bazant and Le that is relevant here, and you've ignored requests to clarify what you mean, I think you should cool it a bit.

Do you mean Bazant, Le, Greening, and Benson (2008), sometimes known as BLGB? Or are you even more confused than we thought?

Yes there was but he was still lost, not being able to find the paper in question, let alone read it.



I put the link to the paper in front of his nose, yet his remaining posts still give no evidence he ever looked at the paper.


>>>>>>>>>>>>>


I have never seen a post by him that demonstrated he ever was able to locate the paper yet he produced memes on the paper's meaning that were mindlessly repeated for years after the bumbling efforts I quoted. Yet somehow you look at those same quotes and they make sense to you, and you tell me how he made a little slip and fixed it in the next post.



Glen, from what parallel universe are you reading his quotes? Because in this universe there is no evidence he ever understood what he was talking about or even read Bazant and Le. Do you remember what I wrote about casualness when checking facts and lack of awareness being central features of mindless replication of empty memes? Thanks for demonstrating those features yet again.


Or do you remember how I wrote about over-confidence in ones own ignorance? That is what the R Mackey series of posts linked above demonstrate, practically to perfection.

 

[ozeco41]

Meaning he never knew the paper existed until I mentioned it, and therefore never even read it. But such a small detail still doesn't keep him from continuing to lecture on it. But how does one do that if they never read the paper? Well, within this environment all you have to do is give the pre-processed memes he had already given on the wrong paper, written with an entirely different argument 6 years before the paper in question. After all, in this brain-dead environment the peanut gallery won't know the difference anyway.

Your obsession with false global claims and hyperbole again Major_Tom.

I doubt that you will ever limit yourself to legitimate technical comment. Nor will your opponents depart from their primary focus on disparaging you rather than addressing the points of technical fact. And I don't care who started the tit-for-tat name calling.

HOWEVER One of those "peanuts" you disparage in the peanut gallery is ME. And I am not brain dead.

I can tell the difference. In fact IF I ever depart from my own self imposed posting ethics and my preference to discuss the technical issues WITHOUT the half truths and insults that both sides prefer - I could have fun comparing the errors on the debunker side with any errors on your side on the technical facts. I have no doubt you would win the comparison with less technical errors.

Mr R Mackey's entry into this thread should speak for itself to any objective rational thinking person:

The whole line of investigation is ridiculous. What unanswered question does this paper purport to examine? None. Existing, reliable, reviewed scientific literature covers it quite thoroughly. All the made-up acronyms and appeals for attention are no more than fatuous Truther narcissism.

Three false unsupported bare assertions. A compounded lie by innuendo chasing an implied straw-man and a three legged insult.

ZERO value added to debate.

 

[tfk]

I have one more set of questions to which I will be referring through the remaining part of this train-wreck of a thread. ...
Zdenek P. Bazant, Jia-Liang Le, Frank R. Greening and David B. Benson (BGLB), in a recorded dialog with the author. All quotes are from David Benson:

David Benson on WTC1:

Question 1: When making this statement, does David Benson seem aware that the WTC1 upper portion basically dis-integrated very early during the collapse process?

...

Question 30: Does David Benson, within these quotes, make multiple references to the Bazant and Le paper to describe the actual collapse mode of WTC1?

Why is M_T asking the people here what DBB means?????
Why does he not ask DBB?????

Have you asked DBB these questions, M_T?
Did he reply?
If so, what were his answers? If available, C&Ps of his replies, please. NOT your interpretation of his replies.

Is it possible that DBB will no longer reply to M_T?
If so, why?

 

[ozeco41]

Why is M_T asking the people here what DBB means?????
Why does he not ask DBB?????

And why import a discussion from a long dead thread on another forum? If M_T has something to say he should say it here - explicitly - in the form of HIS claim or his response to another claim which is made here. Not by roundabout JAQing.

Have you asked DBB these questions, M_T?
Did he reply?
If so, what were his answers? If available, C&Ps of his replies, please. NOT your interpretation of his replies.

I'll leave those for MT to answer...I haven't waded through the dead thread on that other forum which M_T is "cross forum" linking.

Is it possible that DBB will no longer reply to M_T?
If so, why?

AFAIK DBB is no longer active in 9/11 discussion - his last visit here 2008 and his last post on The911Forum mid 2010. Similar situation as many of those early pioneers. So the issue seems dead as far as DBB involvement. Proving DBB right or wrong irrelevant. The truth or otherwise of the technical facts could be a different matter.

 

[JSanderO]

Proving DBB right or wrong irrelevant. The truth or otherwise of the technical facts could be a different matter.

Perhaps is wrong headed thinking is the basis for current thought it needs to be stopped? It's like repeating the Columbus discovered meme and siting your history book. It may not be relevant that the author of the incorrect narrative is wrong. But it is a problem if the narrative persists.

There is very "new under the sun" and people are usually taking historical "truths" / narratives as settled fact and going forward. There does come a time for a clean break and reputation of the false narrative. You don't have to burn them at the stake for heresy... but clearly calling them wrong, misleading, boneheaded and so on may no be polite but it is accurate.

In any case, the discussion stagnating because few were motivating to understand... they thought it was all figured out. And then of course the childish name calling...

 

[ozeco41]

Perhaps is wrong headed thinking is the basis for current thought it needs to be stopped?

Agreed - my constant theme. Deal with the facts not the blame. No point assigning blame. Especially no point ignoring the factual errors or pretending they don't exist whilst focusing on blaming the "opponents" - especially on those facts where they happen to be correct.

It's like repeating the Columbus discovered meme and siting your history book. It may not be relevant that the author of the incorrect narrative is wrong. But it is a problem if the narrative persists.

...AND it causes ongoing misunderstandings OR supports personal agendas.

There is very "new under the sun" and people are usually taking historical "truths" / narratives as settled fact and going forward. There does come a time for a clean break and reputation of the false narrative. You don't have to burn them at the stake for heresy... but clearly calling them wrong, misleading, boneheaded and so on may no be polite but it is accurate.

I think I agree with all the points you are trying to make. You need to check your proof reading.

In any case, the discussion stagnating because few were motivating to understand...<< I think I may have said that a few times they thought it was all figured out. << Wrongly And then of course the childish name calling... << Fear of learning that you have been wrong must be a strong motivator. Or rather demotivator.

 

[JSanderO]

Apologies.. auto correct and I don't proof... and I am probably dyslexic and suffering from dementia... If you manage to read through my unproofed gibberish I am grateful. Can't edit anyway after the clock runs down.

++++

I really like new ideas which provoke thought. I don't care for the gotcha stuff... and making ANYONE feel like an idiot. That's just mean spirited. And we can see how some very top people are / were demonstrably wrong...and some very unknown ones were demonstrably correct.

We all seem to be way too invested in our egos to make progress in these discussions. We all lose in the end.

 

[ozeco41]

Apologies.. auto correct and I don't proof... and I am probably dyslexic and suffering from dementia... If you manage to read through my unproofed gibberish I am grateful.

Your material is relatively easy.

Given the dubious assertions about those papers - B&V and B&Le - I spent an hour or so reading through their gobbledegook. I prefer not to have to read academic papers which seem to be written complicated to fool the laypersons. BUT I needed to check my memory and see if the opposing comments directed at M_Tom's restated claims were accurate. They aren't - same old misrepresentations or could be misunderstandings.

As you know I've long held - said it many times - the later Bazant papers after B &Z are simply wrong where they apply 1D modelling to the WTC collapses. With only one "cop out" that could be viable if anyone cares to prove it - see recent posts.

My memory was not at fault - it was never likely that it would be given that understanding those papers goes to the heart of the contention over Bazant related misunderstandings.

 

[Crazy Chainsaw]

Apologies.. auto correct and I don't proof... and I am probably dyslexic and suffering from dementia... If you manage to read through my unproofed gibberish I am grateful. Can't edit anyway after the clock runs down.

++++

I really like new ideas which provoke thought. I don't care for the gotcha stuff... and making ANYONE feel like an idiot. That's just mean spirited. And we can see how some very top people are / were demonstrably wrong...and some very unknown ones were demonstrably correct.

We all seem to be way too invested in our egos to make progress in these discussions. We all lose in the end.

Bickering has often stood in the way of Knowledge, and ego ignites bickering like a match to
Gasoline.

MT probably doesn't even know there were three hypothesis tested by the computer
Modeling, fracture waves, do to core miss alinement, striping beams and girders,
From the core, run away floor collapse- ROOSD, and column crushing.
What happened, was a composite of floor collapse and fracture wave.
DBB, didn't subscribe to Banzant, until column crush became best fit for the math
of the model.
DBB loves math, if MT had have been able to speak his language he might
Have gotten though to, him.
Holding a grudge, this long however is exceedingly unhealthy, and serves
No useful goal.

 

[Crazy Chainsaw]

A little quote from DBB on physorg, while working on the model.

Joined: 1-June 06

Then you are simply wrong. In any case, the trussed floors offered so little resistance that leaving them out makes little difference. Apply homogenization of structure to re-derive the B & V crush-down differential equation. Compute E1 as best fits the measured data. You'll still get about 0.5+ GJ per story.

The only place there was cross-bracing was on the mechanical floors and below about floor 11. And 14 stories with the additional mass of the upper mechanical floors and hat truss develops the necessary 0.5+ GJ of kinetic energy after falling at (2/3)g for about 2 meters. Yup. Punches right through the concrete floors in the core.

NIST is not the only source of physics or structural engineering. Just because they did not say something does not mean it is relevant.

While I can understand NEU-FONZE's objections to FEA, I don't agree with him regarding NIST's analysis. I do agree with him that sometimes the sections of NCSTAR1 seem to contradict each other. Inevitable in such a large, multi-authored report series...

Edited to add: Aha! In the above I am assuming that the mass of the trussed floors is simply moved elewhere. Other wise, one would not have the drops that were measured. So maybe I am really not very interested in your thought experiment. For without the floors, the exterior wall could not stand. Neither could the core stand alone...

 

[JSanderO]

A little quote from DBB on physorg, while working on the model.

Joined: 1-June 06

But he is wrong... the core could stand alone without the OOS flooring or the facade...

 

[Crazy Chainsaw]

But he is wrong... the core could stand alone without the OOS flooring or the facade...

Did they or did they topple, shortly after the floors collapsed, because of weld damage and bracing removal as was indicated in the model?

 

[GlennB]

But he is wrong... the core could stand alone without the OOS flooring or the facade...

This certainly isn't what I believed I had learned over the years. My understanding is that wind shear would have brought it down.

 

[ozeco41]

A little quote from DBB on physorg, while working on the model.

Joined: 1-June 06

Quote:

Then you are simply wrong. In any case, the trussed floors offered so little resistance that leaving them out makes little difference. Apply homogenization of structure to re-derive the B & V crush-down differential equation. <<Wrong Model Compute E1 as best fits the measured data. You'll still get about << Remember how any times I"ve said "right results for wrong reasons because the mechanism may be insensitive to variations. 0.5+ GJ per story.

No need to keep posting for my benefit evidence that Benson was wrong.