Merged Applicability of Bazant's model to the real world

[Major_Tom]

It is true that, as of now, BV, BL and BLGB effectively serve as published propaganda. It doesn't matter whether the authors intended them to be or not. It doesn't matter if they are even aware of it.

BL and BLGB both claim to prove that allegations of demolition are false by using an incorrect progpagation mechanics based on "buckle down, then buckle up" and a series of straw man arguments. This is a fact.


Therefore, I claim that these papers effectively serve as propaganda in their present form.

I have read many posts by Frank Greening and I find him to be quite honest and a very good researcher. In fact, I post his e-mail exchanges with Steven Jones on my website on the subject of red-grey chips and microspheres. Very interesting exchanges. I have zero problems or complaints with Frank Greening.

My point is, the papers still effectively serve as propaganda, despite the author's best intentions because they are incorrect and make false statememts about "proving" the accusations of demolition are absurd. That is a fact.

 

[ozeco41]

Great. Then ask for it to be moved to the appropriate sub-forum, we are discussing 9/11 conspiracies here...

I understand the attempt to finesse the logic - I tried the same trick in a recent post but I was not serious.

As you must be aware discussion of technical matters which are subsets of the 9/11 matters is accepted. It would be a dead old forum if technical discussions were barred. The current topics index with sequence numbers added:
#1 "Applicability of Bazant's model to the real world"
#2 "9/11 Bee dunkers are unclear: Did Building 7 crash into other buildings as it fell?"
#4 "8 out of 8 at Citgo station"
#6 "Flight 77 should have knocked out more columns in the Pentagon?"
#7 "NORAD and how transponders work "
#9 "Proof of Photomanipulation" .

So six out of the first nine current topics are technical sub set discussions. Where do you want to draw the line? "anything rational posted by a person accused of being a truther is barred?"

...Once again this topic is not valid for this sub-forum...

...see above. That's a lot of "not valid" topics currently under active discussion. Have you posted your "off topic" claim in any of those?

...No it was a great post and while you may tolerate the coyness of Major Tom and Femr, we certainly don't have to.

..so their implicit tactic of irritating is working?

 

[Major_Tom]

I started a thread called "3 Bazant WTC papers debunked". It was moved here.

This thread would be a big embarassment for many of the regular posters in this forum. That is probably why it is not allowed it's own thread.


It is interesting that the thread seems effectively censored, yet you claim it doesn't belong in this forum. It is obvious why people don't want it here.

It destroys the illusions in the authority of the official 9/11 scientific guru. Now he is just another man with many wrong opinions, not a God at all.

Certainly not offering the "proof" he claims.

 

[femr2]

so their implicit tactic of irritating is working?

A rather unnecessary (and untrue) accusation.

Given the volume of crap that gets slung my way I think I am particularly tolerant, patient and polite.

Whilst there are, I'm sure, particular items we may not agree upon (and don't necessarily need to agree upon) it's refreshing to see a few folk here that (in general) simply discuss the detail in hand. A much more productive mode of discourse. Anything less is best described as *playing* imo, and I don't really have much time or inclination for that.

I encourage others to adopt your stance.

 

[ozeco41]

.....so their implicit tactic of irritating is working?

A rather unnecessary (and untrue) accusation....

We have discussed this matter previously.
Don't miss the significance of 'implicit' - I did not think it necessary to explain that a tactic can be implicit in the structure of discussions whether or not it is intentional.

...and how else was I to get across the not too subtle hint?

...Given the volume of crap that gets slung my way I think I am particularly tolerant, patient and polite...

Yup. About 4:1 in M_T's case - crap thrown his way v his responses. And you are more careful.

...Whilst there are, I'm sure, particular items we may not agree upon (and don't necessarily need to agree upon) it's refreshing to see a few folk here that (in general) simply discuss the detail in hand....

Yes again.

...I encourage others to adopt your stance.

Thank you.

In light hearted moments I recall the notice my staff once placed on my office door:

"There are two groups of people in this world. Those who agree with me and those who are wrong."

They had several others in similar vein. I think they were joking....

 

[beachnut]

I started a thread called "3 Bazant WTC papers debunked". It was moved here.

This thread would be a big embarassment for many of the regular posters in this forum. That is probably why it is not allowed it's own thread.


It is interesting that the thread seems effectively censored, yet you claim it doesn't belong in this forum. It is obvious why people don't want it here.

It destroys the illusions in the authority of the official 9/11 scientific guru. Now he is just another man with many wrong opinions, not a God at all.

Certainly not offering the "proof" he claims.

Off topic and sour grapes. If you were not suffering from the delusion of CD, you would stop making up attacks on work you can't comprehend.

You tripe was not censored, it was a big lie moved here. You made a failed thread based on ignorance and you are lucky the mods moved your nonsense here. It belongs in the bit bucket.

You have a biased delusion based on your conclusion the WTC complex was CD. You are lucky the mods are not engineers, your entire thread was off topic, not a thing to do with 911. Your thread was a weak and failed attack on models you can't comprehend. If this was not true, you would publish your failed claims in a real journal.

You cry censorship, but your work is poppycock, attacks on models you can't refute. Your failed claims don't need another thread to discover they are nonsense. Heiwa got published, albeit a letter, his nonsense failed. When will you take the big leap to show more engineers what you have?

Bazant's model is applicable to the real world, your CD delusion is not.

 

[Major_Tom]

Like I said, to most regular JREF posters it does not matter if BV, BL and BLGB are correct or not. Most posters couldn't read the papers anyway.

What is important is that it appears to be correct and authoritarian. It is the illusion that must be preserved. The illusion of expertise and intellectual superiortiy, the illusion of "proof". The illusion of the Wizard of Oz.


It is probably not even about saving face like I mentioned before, but more about preserving the illusion that these questions were decisively answered by the scientific establishment.


Can we admit that the buckle down, then buckle up 1-D mechanics in BV, BL and BLGB has nothing to do with WTC1 and 2? That Dr Bazant never "proved" what he claimed to prove?

Some of us are ready. I've been ready since first posting in May.

But I'm sure that the same false claims about Bazant's papers will be repeated by the same posters. They will constitute the louder "majority" and the same illusions will persist.

That is how propaganda works. And I can prove it.....


Watch how people will appeal to "expertise" and the great "peer review process" . Such "esteemed" Drs must be correct. The "whole enginneering community"...and other such blind appeals to father figures.

Why? Because that is what the BV, BL and BLGB papers represented anyway, the illusion of "scientific proof". They could have told you the sun rises in the west and it wouldn't have mattered much.

 

[W.D.Clinger]

Steady there - not so fast. The trap of reading only recent posts.

Sure, I could have missed the post(s) in which you gave your answer to the follow-up question asked at the end of this post. If so, then I apologize for asking it again.

Preliminary comment - in addressing "are applicable" I clearly distinguish "applicable to WTC" from "applicable to generic conventional buildings".

With that proviso and as tightly as I can summarise:
I am in 98% agreement with what seems to be the prevailing opinion of Bazant and Zhou. That is that it represents a valid 'limiting case'. It shows that there was an overwhelming surplus of energy available to ensure that WTC Twin Towers collapse would progress to global collapse once started. The '98%' reservation because one of Bazant's assumptions is in the unsafe direction BUT I still think he is right overall. Also some of his descriptive stuff in BZ is wrong but it does not affect the conclusions.

I am of the view that, on the surface, BV cannot apply to WTC collapse but is valid for the 'generic building model' which BV used in their paper. That 'generic model' treats the falling block and the lower tower as discrete sort of homogeneous entities with the columns acting in integral concert with the floors. That was certainly not the case for WTC Twin Towers. So my position is BV applicable to generic buildings of conventional construction, not applicable to WTC1&2.

I have left it open for two ways to change my opinion. (Change it to bring WTC into valid application of BV)
1) someone show me that Bazant's maths allows for the case at WTC where the columns were scarcely involved. (I am 95% certain that is not so.); AND
2) I have suggested a method how the actual WTC collapse mechanism may be able to be tested under BV.

The homogeneity was their explicit simplifying hypothesis (4), which doesn't seem altogether unreasonable to unqualified lay folk like me.

As for your complaints about the columns, I know Bažant and Verdure attempt to motivate their model by talking about the columns, but it looks to me as though simplifying hypothesis (4) folds all effects of the column impacts into F_c. With that abstraction, I don't see how the source of F_c could have much effect on their mathematical model. That impression would seem to be confirmed by their short sections on Usefulness of Varying Demolition Mode and Analogous Problem---Crushing of Foam.

So it seems to me that you're complaining about an issue that might reduce an estimate of F_c but is otherwise mostly irrelevant to the mathematical model presented by BV 2007. If you have already explained why the source of F_c matters for that model, then I apologize for bringing this up a second time, and hope you will direct me to your original explanation.

BV has the columns in place taking load and being crushed as part of the collapse. And (AFAICS) being crushed at full failure load. So BV presumes full strength of column crushed whereas WTC Real world the equivalent force was not full column load but floor joist failure load which naturally is an order of magnitude less.

How is your scenario not modelled by reduced F_c?

 

[ozeco41]

Sure, I could have missed the post(s) in which you gave your answer to the follow-up question asked at the end of this post. If so, then I apologize for asking it again...

No apology called for - I was merely commenting on the problem inherent in these sequential posts that some of the continuity can be lost.

...The homogeneity was their explicit simplifying hypothesis (4), which doesn't seem altogether unreasonable to unqualified lay folk like me....

..but on the face of it that assumption does not apply to WTC1 and 2. Threfore I questioned it. And the sequence of my recent posts will show that I have expressed no doubt that 'homogeneity' is valid for a conventional generic building. I have expressed doubt that it applies to WTC with two provisos as to how I could modify my opinion. viz:

1. Someone show me how the maths already accommodates it. BTW already accommodates NOT has provision which could be extended to fit WTC. (The reason for that qualifier being the context of this topic discussion where it is being claimed that BV already fits WTC - the issue where my doubts lie.) OR
2. I have myself proposed that fit to WTC could be explicitly ensured by replacing the column full strength by a weaker force which reflects what actually happened.

...As for your complaints about the columns,...

Sorry but it is not "complaints", discussion, investigation, questions, doubts but not "complaints". Complaints belongs with those who are prepared to defend what they think is Bazant et al at any cost to logic and courtesy of discussion. Witness the abusive posts littering the thread by those who would deny me and others the right to ask "How far is Bazant's work applicable in the real world?" I will not aquiesce to such bullying. Nor will I claim complete assurance in areas where I an not 100% certain.

... I know Bažant and Verdure attempt to motivate their model by talking about the columns, but it looks to me as though simplifying hypothesis (4) folds all effects of the column impacts into F_c. With that abstraction, I don't see how the source of F_c could have much effect on their mathematical model. That impression would seem to be confirmed by their short sections on Usefulness of Varying Demolition Mode and Analogous Problem---Crushing of Foam...

The source of F_c is the main difference between application to a generic model and application to WTC. and "Applicability...to the real world [including WTC]" is the topic under discussion.

...So it seems to me that you're complaining about an issue that might reduce an estimate of F_c but is otherwise mostly irrelevant to the mathematical model presented by BV 2007....

"complaining"?? see previous.

....but the source of the resistance and its magnitude are the core issue of interest in determining how far Bazant is applicable to WTC.

...If you have already explained why the source of F_c matters for that model, then I apologize for bringing this up a second time, and hope you will direct me to your original explanation....

..again no apology required. My position re-explained in earlier parts of this post.

...How is your scenario not modelled by reduced F_c?

...which is exactly what I have proposed myself but have had no response prior to your comments which do, at least, approach the issue.

 

[ProBonoShill]

I understand the attempt to finesse the logic - I tried the same trick in a recent post but I was not serious.

As you must be aware discussion of technical matters which are subsets of the 9/11 matters is accepted. It would be a dead old forum if technical discussions were barred. The current topics index with sequence numbers added:
#1 "Applicability of Bazant's model to the real world"
#2 "9/11 Bee dunkers are unclear: Did Building 7 crash into other buildings as it fell?"
#4 "8 out of 8 at Citgo station"
#6 "Flight 77 should have knocked out more columns in the Pentagon?"
#7 "NORAD and how transponders work "
#9 "Proof of Photomanipulation" .

So six out of the first nine current topics are technical sub set discussions. Where do you want to draw the line? "anything rational posted by a person accused of being a truther is barred?"


...see above. That's a lot of "not valid" topics currently under active discussion. Have you posted your "off topic" claim in any of those?
..so their implicit tactic of irritating is working?

Of course technical matters will be discussed here, the caveat is, they have to be related to 9/11 conspiracy theories.

I'm not sure how this thread qualifies.

Where's the conspiracy?

Maybe I'm going about this the wrong way.

Am I to believe that Bazant supposedly committing a few minor errors (and I'm far from being convinced he has) is equivalent to ZOMG INSIDE JOB!!!!!??????????


As for their implicit tactic of irritating , I believe you're mistaken, I'm not irritated in the least.
We all know they will attempt to back in CD at some point (a quick look at their past makes this evident) you can continue to ignore it if you like , I choose not to.

 

[ozeco41]

...As for their implicit tactic of irritating , I believe you're mistaken,....

So does femr2 - see his earlier post - and my response.

Your other comments noted.

 

[Major_Tom]

WD Clinger, Bazant himself explains what he uses for F(c) in the closure to BV, which is BL.

BLGB refines the resistance force further. You cannot understand what he does through the papers by looking at BV only.

In BV he first describes it as one or two story buckling, but in the equation it is in an abstract form. In BL (closure to BV) and BLGB he clearly applies it to column buckling.

In fact, that is the origin of the idea of "no early crush-up", it really means "no buckle-up". If F(c) wasn't based on buckling, no "crush down, then crush up" concept would exist in his writing. The "proof" of no early crush up involves comparing the "upward force" to the capacity of the upper columns to resist buckling. He concludes that because the upward force isn't sufficient to overcome the upper columns, no early crush up is possible.

Explained very well in BL and BLGB.

 

[W.D.Clinger]

...The homogeneity was their explicit simplifying hypothesis (4), which doesn't seem altogether unreasonable to unqualified lay folk like me....

..but on the face of it that assumption does not apply to WTC1 and 2. Threfore I questioned it. And the sequence of my recent posts will show that I have expressed no doubt that 'homogeneity' is valid for a conventional generic building. I have expressed doubt that it applies to WTC with two provisos as to how I could modify my opinion.

The model is one-dimensional, so the assumed homogeneity is vertical. Here is the assumption and its motivation as described by Bažant and Verdure:

(4) The stories are so numerous, and the collapse front traverses so many stories, that a continuum smearing (i.e., homogenization) gives a sufficiently accurate overall picture.

...As for your complaints about the columns,...

Sorry but it is not "complaints", discussion, investigation, questions, doubts but not "complaints". Complaints belongs with those who are prepared to defend what they think is Bazant et al at any cost to logic and courtesy of discussion.

So neither you nor I have any complaints about Bažant et al.

I, however, have quite a few concrete criticisms of Bažant and Verdure's paper. Unfortunately, my concrete complaints criticisms involve fairly insignificant errors, most of them easy to fix. I'd like to have stronger grounds for disliking the paper.

Witness the abusive posts littering the thread by those who would deny me and others the right to ask "How far is Bazant's work applicable in the real world?" I will not aquiesce to such bullying. Nor will I claim complete assurance in areas where I an not 100% certain.

Fine. Perhaps you can understand why I am not inclined to acquiesce to your incomplete assurances.

The source of F_c is the main difference between application to a generic model and application to WTC. and "Applicability...to the real world [including WTC]" is the topic under discussion.

No, the source of F_c is part of the motivation for the model. If a model is reasonably accurate given its assumptions, then it should be possible to apply the model to any situation that comes sufficiently close to satisfying those assumptions, even if the situation to which the model is being applied bears no other resemblance to the motivating example.

....but the source of the resistance and its magnitude are the core issue of interest in determining how far Bazant is applicable to WTC.

The magnitude is relevant, but I don't see why its source should be. As explained above, the explanation you have given so far fails to convince.

...How is your scenario not modelled by reduced F_c?

...which is exactly what I have proposed myself but have had no response prior to your comments which do, at least, approach the issue.

To argue that a mathematical/scientific/engineering model does not apply to a real situation, you need to identify an error in the model's mathematics, science, or engineering, or you need to identify an assumption of the model that is violated by the real situation.

To identify an assumption of the model that's violated by the real situation, you have to identify the assumptions of the model. That can be difficult, especially when the model is described so poorly. It seems to me that you have been confusing the BV model's motivation with its assumptions.

You have also asserted that explicit assumption (4), quoted above, does not hold for the WTC towers. That would be relevant for collapse initiation, but my layperson's intuition says vertical homogeneity might be a reasonable approximation for the WTC towers when describing their collapse progression. If a qualified expert were to explain otherwise, I would listen.

Bažant and Verdure probably made some tacit assumptions. That usually happens, even in papers that are much better written. If a qualified expert were to identify tacit assumptions of their model that do not hold for the WTC towers, I would listen to that also.

I'm not denying your qualifications or expertise, and I know you think you've provided adequate explanations of your position. What I have written above may help you to understand why I am not fully convinced by your arguments.

 

[ozeco41]

...I'm not denying your qualifications or expertise, and I know you think you've provided adequate explanations of your position. What I have written above may help you to understand why I am not fully convinced by your arguments.

Comments noted.
My aim was to observe a discussion. For whatever reasons I joined in the discussion - if you go to the original OP the topic arose from a comment I had made and one which I did not realise was as contentious as it seems to be. So I put forward my own opinions.

Your understandings seem to come from a basis in the mathematics and abstract concepts about modelling. Nothing wrong with that and you are in the majority of those who could make a meaningful contribution on this forum. Contrary to many engineers I usually start from understanding the physical realities and moving towards the more abstract. The gap between the two can be difficult to bridge.

The differences may remain unresolved because the polarised climate and limited on topic input makes progress difficult. And I am not the person to dominate discussion on a topic which is of secondary interest to me.

So from here you may become more convinced that there is something in my concerns. Alternatively someone may show me where my understanding is off target.

 

[Major_Tom]

WDC, Bazant wrote two other papers after BV. You'll find most of the more obvious mistakes in those.

I notice you only refer to BV. Is that all you have read?


>>>>>>>>

Since Bazant wrote his papers some researchers have actually mapped real WTC1 collapse progression rates for the first time.

I mentioned this before. This is the solution that Dr Bazant had been seeking. He believed that only the first 3 seconds of collapse and seismic data were available, but he was incorrect.

If anyone is thinking of making a mathematical model of OOS propagation rates, traits of the observed propagations in WTC1 and 2 have already been collected.

For example, there is a rapid rise to a terminal velocity, and that velocity seems to be maintained throughout the progression.

All this is new information. If you think this data fits the crush down, then crush up mathematical model of Bazant, then we have the data you will need to compare it to.


In my opinion, there are more creative ways to express the actual propagation mathematically, since we know much more than Bazant did. He did not know the solution in advance like we do. He did not consider the ROOSD process, which is a more controlled, confined and regulated process than some general chaotic crush down.

The ROOSD process can definitely be modelled by someone with the talent and resources. It is an extremely confined, repetitive process.

We have much, much more information than Bazant had when he wrote the papers. Why try to fit these new ideas into that old musty shoe box?

 

[Major_Tom]

In addition, this terminal velocity behavior has already been roughly modelled:

This is using the WTCCS Asynchronous Impact Crush-Down Model at femr's website.

From this post:
http://the911forum.freeforums.org/wtccs-asynchronous-impact-crush-down-model-t178-90.html#p10967


From the perspective of more current research, it seems silly to try to salvage the Bazant buckle down, then buckle up progressive collapse equations by stuffing these new concepts into those.

Let's not put new wine into old wineskins.

 

[ozeco41]

WD Clinger, Bazant himself explains what he uses for F(c) in the closure to BV, which is BL.

BLGB refines the resistance force further. You cannot understand what he does through the papers by looking at BV only.

In BV he first describes it as one or two story buckling, but in the equation it is in an abstract form. In BL (closure to BV) and BLGB he clearly applies it to column buckling....

Hence my reluctance to study those papers in depth. For my purposes BZ is easily positioned as 'limiting case' despite a couple of shady bits of logic. But my interest in 9/11 WTC has been on another forum and focussed on explaining 'no demolition' to an audience of lay persons and some sceptical engineers. BV, BL, BLGB don't help me in that pursuit so, prior to this thread, I had not wasted time defining exactly where they do not apply to WTC.

And I am beginning to question my wisdom in entering the discussion.

 

[Major_Tom]

Of all people posting, you do not need to know them in more depth. I believe you understand them enough for your purposes.


But I have clearly shown that detailed knowledge of the equations is necessary to see through all the BS.

There is no reason for anyone to argue that knowledge of these papers is unimportant since this forum is possibly the largest single source of spreading incorrect information about the papers. I call this propaganda, whether the incorrect information is spread intentionally or unintentionally.

Also, if you find the noise tiresome, then you may understand my point of view, since for me it's been about 8 months of receiving insults and observing mass denial.

 

[femr2]

That is how propaganda works. And I can prove it.....

These kind of statements don't help MT.

 

[femr2]

As for your complaints about the columns, I know Bažant and Verdure attempt to motivate their model by talking about the columns, but it looks to me as though simplifying hypothesis (4) folds all effects of the column impacts into F_c. With that abstraction, I don't see how the source of F_c could have much effect on their mathematical model. That impression would seem to be confirmed by their short sections on Usefulness of Varying Demolition Mode and Analogous Problem---Crushing of Foam.

...

If F(c) wasn't based on buckling, no "crush down, then crush up" concept would exist in his writing. The "proof" of no early crush up involves comparing the "upward force" to the capacity of the upper columns to resist buckling. He concludes that because the upward force isn't sufficient to overcome the upper columns, no early crush up is possible.

Colour change mine.

I'd need to look at the force function again to state anything specific.