Moderated Continuation - Why a one-way Crush down is not possible

[Dave Rogers]

Dave, this was obviously a rough back of the envelope calculation to show just why the core was self-supporting. I did not say it could support 37 billion pounds, just that that size column would need that kind of a load to buckle, meaning it would not. It would have failed by compressive rupture first and is out of the realm of buckling.

Here is a calculation for a 137 foot x 87 foot rectangular column x 1440 foot high with just 12 inch walls. The calculation is converted to inches with a 1,644 inch x 1,044 inch rectangular column x 17,280 inch high.

The moment of inertia I = 1/12bh^3. The hollow area MOI about the least radius of gyration is subtracted from that of the exterior dimensions to find the MOI of the hollow section with 12 inch walls and it is 12.628 x 10^9 in.^4.

The critical buckling load equation is F = (Pi^2 x E x I)/(K x L)^2

Since it is fixed at one end and free at the other K = 2.0. The modulus of elasticity is 29 x 10^6 psi for steel. In this case F = 3.02 billion pounds (which is at least 3 times and possibly 5 times the entire weight of a tower). This simply means it is out of the range of buckling, since it would obviously fail by compressive rupture first.

You can cut lots of holes in the side of this 12 inch thick wall column as long as all slenderness ratios are such that local buckling will not occur, which is what the X-Y lattice structure of the core did. It limited buckling of the columns to near their compressive yield stress by keeping their slenderness ratios low. Since the columns would not yield with less than 3 times the load on them the core was self-supporting.

I've edited the above to correct the typo you identified.

The problem I have with this is that the structure you're starting with has virtually no resemblance to the structure you're using it to represent. You've started from the argument that a solid column and a square tube have roughly the same buckling strength, yet when you actually do the calculation you find that they differ by more than a factor of ten. You're now asserting, without calculations to back it up, that a structure still vastly stronger and heavier than the actual core, with all the structural material concentrated at its edges where it can provide the most resistance to buckling, is again similar in strength against buckling ratio. In effect, you're handwaving away a correction factor that, as you've already shown, can amount to more than an order of magnitude.

I'll be the first to hold my hand up and say that I have absolutely no idea how to calculate the stiffness of the WTC cores. However, your bare assertion that they must behave similarly to two different structures whose buckling strength differs by more than an order of magnitude is simply not credible. Given the extreme differences, you can't claim you've proven anything unless you've analysed at least a reasonable approximation to the actual structure.

Dave

 

[Gamolon]

You're a proven liar Tony. Show us the documentary.

Hey Tony,

Have you found the quote from Skilling saying that he and his people did analysis on how fire would effect the structural steel in the towers?

You seem to just make stuff up as you go along.

 

[Dave Rogers]

Late's take your paper. Your first error is that you conflate a limiting case analysis with reality. Via a flawed-ridled analysis you conclude that the limiting-case scenario did not occur in reality. Surprise. You construe this as an argument in favor of CD (Non Sequitur: the conslusion doesn't follow from the premisse). The analysis is flawed. You use a 166 ms sampling interval to find a 13 ms event. You fail to do error analysis (whch given the low spatial and temporal resolution and going to the first and second derivative of the observed quantity is fully warranted), you superimpose the limiting-case jolt on your plot expressing your opinion on how the graph should look where the jolt present, thereby implicitly assuming it isn't there (Circular Logic).

You missed one. As I've already pointed out more times than I care to remember, the paper also assumes a radically different collapse progression than what was actually observed, in that it assumes no rotation of the upper block; and I've shown that, for a particular set of assumptions, the jolt intensity is critically dependent on the angle of rotation, and decreases very strongly at very small angles. Therefore, the whole analysis is geometrically flawed.

Dave

 

[hokie]

Where have you seen me discussing what you say here?

You didn't reject Gravy's connection to the comments.

I have read the ridiculous claims made in papers about 'incredible amounts of energy released' and 'pyroclastic flows'. They papers remind me of your work. Simplistic models applied incorrectly to generate nonsense.

I also read the jolt paper. My recommendation to you is to determine why your paper does not reflect what happened and to go back and correct your paper.

As far as the oft repeated claim that you did not provide error bars goes a comment from you at another forum has you stating that every 5th frame was used to collect the data for the plot because motion could not be determined using every frame.

To me this says that you knew there was a lack of precision in your data and you chose to avoid examining it.

 

[Gamolon]

Here is a calculation for a 137 foot x 87 foot rectangular column x 1440 foot high with just 12 inch walls.

I missed this the first time and went back to read it after seeing Dave's comments above...



I didn't know the core of the towers was constructed of 12" thick steel plate with no openings/connections from top to bottom. You know, I think I DO remember this core being mentioned in the same documentary that Christophera saw years ago. In that same documentary, Skilling said that they did fire analysis on this "plate core" and said it would NEVER come down. Even if they tried to demo it using explosives.

 

[BasqueArch]

Tony Szamboti
Pardon me if I take your silly comment here with less than a grain of salt. I am wondering if you ever even read anything I wrote, much less understood any of it, as your post here provides no basis for what you say.

Yes. I've read quite a few of your posts here. I've also read your "Missing Jolt" paper. That is the foundation for my assertion.

Let's take your paper. Your first error is that you conflate a limiting case analysis with reality. Via a flawed-ridled analysis you conclude that the limiting-case scenario did not occur in reality. Surprise. You construe this as an argument in favor of CD (Non Sequitur: the conslusion doesn't follow from the premisse). The analysis is flawed. You use a 166 ms sampling interval to find a 13 ms event. You fail to do error analysis (whch given the low spatial and temporal resolution and going to the first and second derivative of the observed quantity is fully warranted), you superimpose the limiting-case jolt on your plot expressing your opinion on how the graph should look where the jolt present, thereby implicitly assuming it isn't there (Circular Logic).

Thank you.

FATHER SARDUCCI TAKES SZAMBOTI'S CONFESSION AS CROWD PRESSES IN TO HEAR PENITENT’S WHISPERED WORDS.


"Heiwa is wrong Gravy was right"
*cough*
"and I knew it"​

 

[tfk]

Basque,

You know what this means, don't you?

Zdenek Bazant to Receive Timoshenko Medal

http://www.mccormick.northwestern.edu/news/articles/545
Zdeněk P. Bažant, McCormick Institute Professor and Walter P. Murphy Professor of Civil and Environmental Engineering at Northwestern University, will be awarded the prestigious Timoshenko Medal by the American Society of Mechanical Engineers.

Bažant discovered the non-statistical (energetic) size effect on the strength structures consisting of brittle heterogeneous materials such as concrete, fiber composites, tough ceramics, rock, sea ice, rigid foams, and many materials on approach to nano-scale. He formulated a simple size effect law used for structural design and material characterization. He is known as a world leader in the research on scaling in solid mechanics.

The Timoshenko Medal was established in 1957 and is conferred in recognition of distinguished contributions to the field of theoretical mechanics. Instituted by the Applied Mechanics Division, it honors Stephen P. Timoshenko, world-renowned authority in the field, and it commemorates his contributions as author and teacher.

Bažant has already been elected to the American Academy of Arts and Sciences, the National Academy of Sciences, the National Academy of Engineering, the Austrian Academy of Sciences, the Accademia Nazionale dei Lincei (Rome), the Spanish Royal Academy of Engineering, the Engineering Academy of Czech Republic, the European Academy of Sciences and Arts, and the Academia di Scienze e Lettere (Milan). He has also received six honorary doctorates from universities in Boulder, Prague, Karlsruhe, Milan, Lyon, and Vienna.

Bažant will receive the medal at the dinner of the Applied Mechanics Division on Nov. 17.

The American Academy of Arts and Sciences
The National Academy of Sciences
The National Academy of Engineering
The Austrian Academy of Sciences
The Accademia Nazionale dei Lincei (Rome)
The Spanish Royal Academy of Engineering
The Engineering Academy of Czech Republic
The European Academy of Sciences and Arts
The Academia di Scienze e Lettere (Milan)

And now, The American Society of Mechanical Engineers

They're all part of the conspiracy!!!


My God, man. Is there no place that is not infiltrated with these traitors??


Tom

PS. Wait, perhaps it's ONLY the "Applied Mechanics Division" of the ASME...

PPS. It's like a 3rd rate, 1950s Sci Fi movie.

 

[tfk]

Good lord, I think you're right. My only quibble is that the notion of Heiwa refuting Bazant is not much less ridiculous than Bill refuting Bazant. A contest of flea vs. elephant is not all that different from toad vs. elephant.

.
"Bambi vs. Godzilla" springs to mind...

Tom

 

[Heiwa]

In other words, you are making up numbers?

Suppose the structure under observation is WTC2. Can you provide numbers and calculations for that?

No, my numbers concern WTC 1 and are published in my paper at http://heiwaco.tripod.com/nist.htm . Reason being that Bazant and Seffen also deal with WTC 1. Evidently I debunk them easily. Read my paper.

 

[aggle-rithm]

No, my numbers concern WTC 1 and are published in my paper at http://heiwaco.tripod.com/nist.htm . Reason being that Bazant and Seffen also deal with WTC 1. Evidently I debunk them easily. Read my paper.

Do you know what the word "Evidently" means? I notice you use it a lot, in very strange contexts.

 

[aggle-rithm]

Heiwa and Tony:

Since you're such crackerjack engineers, perhaps you could answer a question that's been bugging me for years.

As an engineer, how would you go about wiring three large buildings that are occupied 24-7 with explosives, taking the following requirements into consideration:

1. No one can notice they are being installed
2. From the time of installation to detonation, they must be completely hidden
3. They must go off without any of the usual outward signs of high explosives, such as shock waves and shrapnel
4. They should leave no trace of evidence in the aftermath, keeping in mind that the rubble will be painstakingly sifted through by law enforcement looking for human remains and evidence

Since engineers have to take costs into consideration, it would also be helpful to know how many man-hours it would take to complete the job. That would give us an idea how many people would have to be silenced in one way or another.

I know demolition isn't your area of expertise, but Heiwa has up to this point been happy to make daring pronouncements about things he is not certified for, so this shouldn't be a problem.

A million dollars goes to whoever can come up with a plausible response. Heck, work together, and win TWO million!

Good luck!

 

[FineWine]

I thought you said you retired from your 911 sophistry Mark. What happened?

Of course, all we see here are your normal disingenuous and tired attempts to discredit anyone who has brought up the fact that 911 was an inside job.

But, it is not a fact that the Islamist attacks of 9/11 were an inside job: it is a falsehood, and an absurd one at that. After almost eight years, your side has failed to produce a shred of evidence supporting its mad claim. Absolutely nothing suggests that 9/11 was an inside job.

 

[FineWine]

The NIST analysis stops at the point where they say the tower was "poised to collapse" so how can you say they already performed the task?

You need to explain why you feel loose debris would provide sufficient force to break up intact structure which was capable of supporting several times the load above it.

There was no deceleration observed by those thirteen floors, so how did they crush the lower structure? The first floor they would contact was built to support those thirteen floors several times over. How could it happen without an ampliication of the load?

I don't believe your claim that the 97th floor was built to withstand floors 98-110 collapsing onto it "several times over." I think you're making up whatever you require to support your terribly flawed argument. You should explain the new principle of physics that allows thirteen collapsing floors to do less damage to the floor below if they've already started to break up themselves.
I realize that you proponents of the New Physics have eliminated gravity from the universe, but wouldn't the momentum of the FALLING floors constitute an amplification of the load?

 

[tfk]

Grizzly, you should look into what mass participation, stiffness, and transmissibility mean in a shock load.

.
Tony,

I'm doing this for illustration & understanding. You can help. I promise that, throughout this, no insults.

Let's start simple.

A lattice cube, 12' on a side, made up of 12 steel beams (about the size of the tower's peripheral columns near the top, i.e., 14" x 14" x .5" thick box beams) on an edge, with some sort of BOLTING connector at each corner. Weight per beam: (4 x 13" x .5" x 144" x 0.3 lb/in^3 = 1100 lbs/beam. Total weight = 6.7 US Tons.

First time, we're gonna drop it onto an intact floor of the WTC. Say, we were to neatly slice off the tower at the 70th floor, where there was no damage, and set the top aside.

Next, we're gonna drop it onto the massively damaged damaged 97th floor of the Towers. You know, the floor that was missing about 1/6th of its columns due to the airplane crash, about 1/3 of its concrete floor, had all the rest of the columns twisted out of shape by fire, plastic creep and (oh yeah) the passage thru the floor of a 120 ton, 500 mph jetliner.

Tell us. What is the difference in load imparted onto the "floor" if the cube were dropped from the same height (say, 12 feet) if the cube was:

1) bolted together with "unobtanium" (infinite strength) bolts.
2) dropped with all the components in the same orientation, but glued together with crazy glue (i.e., no connection strength).
3) bolted together with small, real bolts
4) crushed first into a giant, intermeshed glob and then dropped.

Assume that, when it hits, one corner hits first.

Please be specific as to the stresses and reactions of both the floor & the cube:
1. at point of contact.
2. global response of the floor.

Here's a matrix to help you answer these. Very brief responses are all that is necessary here. I am trying to illustrate the difference between the impact forces on the floor between an assembled, intact piece and the same piece that has been disassembled in a couple of different ways.

FLOOR intact:
1. Unobtanium bolts:
... Response of floor: ____
--- Response of cube: ____

2. Glued components in a cube: ____
... Response of floor: ____
--- Response of cube: ____

3. Steel bolts: ____
... Response of floor: ____
--- Response of cube: ____

4. All components in a crushed mass: ___
... Response of floor: ____
--- Response of cube: ____


FLOOR Damaged:
1. Unobtanium bolts:
... Response of floor: ____
--- Response of cube: ____

2. Glued components in a cube: ____
... Response of floor: ____
--- Response of cube: ____

3. Steel bolts: ____
... Response of floor: ____
--- Response of cube: ____

4. All components in a crushed mass: ___
... Response of floor: ____
--- Response of cube: ____

There's a couple of important points to this that I want to illustrate. We'll build up the model, piece by piece, so that in about 3 steps, we'll be at the WTC upper block.

Tom

 

[Heiwa]

Heiwa and Tony:

Since you're such crackerjack engineers, perhaps you could answer a question that's been bugging me for years.

As an engineer, how would you go about wiring three large buildings that are occupied 24-7 with explosives, taking the following requirements into consideration:

1. No one can notice they are being installed
2. From the time of installation to detonation, they must be completely hidden
3. They must go off without any of the usual outward signs of high explosives, such as shock waves and shrapnel
4. They should leave no trace of evidence in the aftermath, keeping in mind that the rubble will be painstakingly sifted through by law enforcement looking for human remains and evidence

Since engineers have to take costs into consideration, it would also be helpful to know how many man-hours it would take to complete the job. That would give us an idea how many people would have to be silenced in one way or another.

I know demolition isn't your area of expertise, but Heiwa has up to this point been happy to make daring pronouncements about things he is not certified for, so this shouldn't be a problem.

A million dollars goes to whoever can come up with a plausible response. Heck, work together, and win TWO million!

Good luck!

You are a little off-topic! Here we discuss why a one-way crush down is not possible by gravity alone. It seems nobody is able to explain how a little top part C of a structure can one-way crush down the bottom part A, in particular when part C just consist of bolted together wall perimeter and floor sections and a rather solid core.

Actually, a one-way crush down by gravity alone is impossible. So controlled demolition is the only possible cause. How the perpetrators did it is another matter. But I have some ideas in my paper http://heiwaco.tripod.com/nist3.htm . You know, plenty of gangsters also sink ships (to collect insurance) and there are many ways to do that. Same for WTC 1, 2 and 7.

 

[FineWine]

You are a little off-topic! Here we discuss why a one-way crush down is not possible by gravity alone. It seems nobody is able to explain how a little top part C of a structure can one-way crush down the bottom part A, in particular when part C just consist of bolted together wall perimeter and floor sections and a rather solid core.

Actually, a one-way crush down by gravity alone is impossible. So controlled demolition is the only possible cause. How the perpetrators did it is another matter. But I have some ideas in my paper http://heiwaco.tripod.com/nist3.htm . You know, plenty of gangsters also sink ships (to collect insurance) and there are many ways to do that. Same for WTC 1, 2 and 7.

Your paper is worthless nonsense. Stop running and start explaining why you can't grasp what is obvious to everyone sane.

Your Part C consists of the floors including and above the impact floors that have collapsed. They hit, not a huge, imaginary Part A, but ONE floor, the floor immediately below. The collapsing floors crush that next floor in line and add its mass, thereby increasing the momentum of the collapse. The process is repeated, very quickly, until the building is gone.

 

[BasqueArch]

basque,

You know what this means, don't you?

The American Academy of Arts and Sciences
The National Academy of Sciences
The National Academy of Engineering
The Austrian Academy of Sciences
The Accademia Nazionale Dei Lincei (rome)
The Spanish Royal Academy of Engineering
The Engineering Academy of Czech Republic
The European Academy of Sciences and Arts
The Academia di Scienze e Lettere (milan)

and now, the American Society of Mechanical Engineers

They're all part of the conspiracy!!!


My god, man. Is there no place that is not infiltrated with these traitors??

Tom

PS. Wait, perhaps it's only the "Applied Mechanics Division" of the ASME...

PPS. It's like a 3rd rate, 1950s Sci Fi movie.

tfk Exposes Global Cabal Of 9/11 Engineers.
Conspirators Tally So Far Grows To 92% Of The World’s Population.
Truth Movement Awards tfk 10 cds “ Loose Change 12th Edition Recut TinyCut MinorSnip”, KFC Lunch With Richard Gage, Engraved Genuine Reproduction Nanothermite Chip.



Szamboti, Bill, Heiwa, Chandler Flee Dark Sided JREF Shills​

 

[tfk]

Tony,

Regarding calculating the "flexibility of the core alone"...

Calculating whether or not the dang thing would stand on it's own is pretty damn hard. The conclusions got nothing to do with the known dimensions. It is determined by things like tolerences of connections, resulting in accumulated "tilt", straightness of beams, strength & stiffness of cross trusses & interconnections. etc.

Very messy FEA problem. (Actually, a pretty neat FEA problem, once you make these factors variable parameters. )

But you can do a couple of things very easy, very quick, with very good (OK pretty good) accuracy.

You can:

Accurately calculate the moment of inertial of the core using I for box beams and the parallel axis theorem. This would get rid of some very BAD assumptions on your part.

Specifically, "I" is, in fact "additive" for materials equal distance from the centroid. And a solid tube at the outer dimensions of the rectangle of the core has got a couple orders of magnitude more material at that location than a continuous thin-walled tube.

Second, you are asking about the stiffness of the core itself. A solid wall of material, even a thin wall, is WAY better connection, and therefore WAY stiffer, than individual hollow box columns with cross bracing. You model is very poor.
___

But the second thing that you can do easily is to compare the Moment of inertial of the whole building to the Moment of Inertia for just the core.

Use the parallel axis theorem, calculating I for the Core, the outer wall using some intermediate, constant wall thickness. (Close enough) Add in "I" for the concrete floors. Then you've gotta add in some equivalent intermediate stiffness for the cross bracing, taken from "free standing column stiffness" nomographs.

My SWAG says the concrete will be responsible for >50% of the stiffness. My SWAG says that the stiffness of the whole building is about 20x the stiffness of the core alone.

I'd do the calc, but I don't really care. It looks like about 15 minutes worth. Less time than writing up a post.

Tom

 

[tfk]

You are a little off-topic! Here we discuss why a one-way crush down is not possible by gravity alone. It seems nobody is able to explain how a little top part C of a structure can one-way crush down the bottom part A, in particular when part C just consist of bolted together wall perimeter and floor sections and a rather solid core.

Actually, a one-way crush down by gravity alone is impossible. So controlled demolition is the only possible cause. How the perpetrators did it is another matter. But I have some ideas in my paper http://heiwaco.tripod.com/nist3.htm . You know, plenty of gangsters also sink ships (to collect insurance) and there are many ways to do that. Same for WTC 1, 2 and 7.

.
You do have a lot of damn gall saying "here we discuss ..."

YOU don't discuss anything.

You avoid discussion at all costs. Unless it's in your momentary self interest. And, with annoying regularity, issue your skipping record, self-promoting, "read my paper".

Along with the "Bill Smith" level of arrogant stupidity "I prove Bazant wrong ...".

So, please. Continue your open loop Rainman-ing. But don't dare attempt to orchestrate or influence in the slightest "what we discuss here".

You voluntarily withdrew from that conversation a long, LONG time ago.

tom

 

[FineWine]

.
You do have a lot of damn gall saying "here we discuss ..."

YOU don't discuss anything.

You avoid discussion at all costs. Unless it's in your momentary self interest. And, with annoying regularity, issue your skipping record, self-promoting, "read my paper".

Along with the "Bill Smith" level of arrogant stupidity "I prove Bazant wrong ...".

So, please. Continue your open loop Rainman-ing. But don't dare attempt to orchestrate or influence in the slightest "what we discuss here".

You voluntarily withdrew from that conversation a long, LONG time ago.

tom

Do you think he'll ever address my question about the relative sizes of his Part C, the collapsing floors, and the floor immediately below? Will he acknowledge that his Part A is an imaginary concept?