Szamboti's Missing Jolt paper

leftysergeant said:
Part of our problem here may be that it is assumed that there would be a jolt, as in verinage, because we are thinking of thje upper-block core columns taking part in driving the collapse, as do all the columns in a building taken down by verinage.

Problem with this thinking is that it is driven mostly by the floor slabs. Once enough of them collapsed or slumped out of their seats, starting a cascade of failures, any jolt would be rather minimal.

You don't even need the rest of the block to drive collapse of the floor slabs.
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The structure of the towers was more than stiff enough to transmit the deceleration to the roofline. In fact, it was probably stiffer than the Verinage buildings which all show a deceleration.
 
rwguinn said:
Tony's problem is a whole lot more basic than that. He is hung up on principles a 3rd year engineering student will breeze past.
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On a relative scale based on what I see you say here, if I am hung up on principles a 3rd year engineering student could breeze past then you have to be back at the kid taking his placement test to get into college.
 
Tony Szamboti said:
The structure of the towers was more than stiff enough to transmit the deceleration to the roofline. In fact, it was probably stiffer than the Verinage buildings which all show a deceleration.
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So you're saying that the WTC towers were stiffer than multistory reinforced concrete buildings? That's what you're going with? Really?

:dl:
 
Posted by Myriad
<snip>
Come to think of it, buildings are so fragile that many of them can actually be damaged by earthquakes! A mere few seconds of shaking! Can you imagine an empty cardboard box being damaged by being shaken by an earthquake (that is, without something else falling on it)? Ridiculous! Cardboard boxes are vastly stronger, that's why many of them able to support hundreds of times their own weight.

Intuition is usually very unreliable when it comes to effects of scale. Incredulity based on such intuition will lead even well-meaning and intelligent people to ridiculous conclusions. Correct quantitative analysis and intellectual honesty in accepting the results of such analysis even if counterintuitive, are the usual ways around that problem. But developing better intuition might also help.
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Thank you Myriad . It’s not obvious that small inputs can have large effects. The Towers were structurally vulnerable to just the type of event that occurred; 32,000 sf of wispy floor bar joists with no interior columns or beams.

T. Samboti mistakenly believes Huge Building requires Huger Forces to knock it down. He believes “upper block cannot crush lower block,“ like Gage’s humiliating clueless boxes demonstration.

Please review the following video.
Like structural judo, one small cause has an enormous effect.

The video is over when the fat guy laughs.



I’m sure T. Szamboti can provide the math to disprove what you’re seeing.

---------------------------------------------------------------
You cannot reason someone out of something they were not reasoned into - Swift
 
Tony Szamboti said:
If you want to have an e-mail debate through DGM that is fine with me. He is a non-truther and offered that in this thread today. He has my e-mail address.
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That would be OK with me.

tfk PM me if you want my email address.

Tony, would it be OK for you to debate here if tfk confided his identity to me?
 
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Tony Szamboti said:
Many people have measured this fall in WTC 1 now and it is evident that there was no deceleration and that the upper section continuously accelerated during its fall.
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Oh Tony Szamboti, you silly man. You just got done arguing the upper section was decelerated at 32.2 ft/s^2 for the last 40 years! Now "...there was no deceleration..." You can't have it both ways Tony Szamboti.
 
DGM said:
That would be OK with me.

tfk PM me if you want my email address.

Tony, would it be OK for you to debate here if tfk confided his identity to me?
Click to expand...

No, but I would agree to an e-mail debate where if there is a resolution it can be posted.
 
3bodyproblem said:
Oh Tony Szamboti, you silly man. You just got done arguing the upper section was decelerated at 32.2 ft/s^2 for the last 40 years! Now "...there was no deceleration..." You can't have it both ways Tony Szamboti.
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I am saying the deceleration required to amplify the insufficient static load above, so that it can demolish the columns below, needs to be significantly greater than 32.2 ft/sec^2.

There needs to be a higher force than the static weight to break the columns and the only thing that can change is the deceleration as the mass is constant.

You apparently didn't understand as it seems has been the problem with a number of others. I would be careful who I called silly until I was sure I understood what was being said.
 
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Sam.I.Am said:
So you're saying that the WTC towers were stiffer than multistory reinforced concrete buildings? That's what you're going with? Really?
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The modulus of elasticity of steel is approximately seven times that of concrete. I would bet you didn't know that.
 
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Regarding my reference to one of his posts on the first page of this thread, Dave Rogers wrote:
Dave Rogers said:
Funnily enough, when I posted that, Tony's response was to pretend it was my misunderstanding, but then, when it was confirmed by a couple of people he was prepared to listen to, to revise the paper so as to eliminate the smoothing function.
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They may have removed the smoothing function from the prose, but they left the misleadingly smoothed data in Figures 2, 3, 4, 5, and 6. Until you posted the above, I had assumed your earlier post was referring to the smoothing evident in those figures. I guess the early draft you saw had discussed the smoothing in the text of the paper as well, which would have been less misleading than what they actually published.

Here is Figure 5 from their paper:

figure5original.jpg


Although Figure 5 above claims to present "actual measured velocity", that is a lie. Here are the actual measured velocities, as computed directly from their unsmoothed data in the table on pages 6-7:

figure5honest.jpg


Their sampling rate was only 6 Hz, and their sampling error for distances was at least the 0.88 foot distance corresponding to a single pixel, so their sampling error for velocities is at least 5.28 ft/sec. That is also the quantum for their velocity measurements. A horizontal interval of 1/6 second doesn't mean anything unless the velocity measured for the following 1/6 second increases by two quanta or more (10.56 ft/sec).

As can be seen from the unsmoothed data in my graph, there appear to have been three mild jolts around 1.00, 1.33, and 1.67 seconds. Tony's expected delta-V of 13.13 ft/sec is shown in the dashed line, followed by the subsequent 1g acceleration implied by their model (instead of the incorrect reduced acceleration shown in their Figures 5 and 6, which was also incorrectly labelled as "reduced velocity"). If you compare the solid and dashed lines at 2 seconds, you will see that the sum of the three (or more) mild jolts was equal to Tony's expected jolt to within quantization error.

Hence jolts summing to the magnitude Tony expected have been there in his data all along, but Tony's expected big jolt was divided into at least three smaller jolts. That confirms the consensus hypothesis that the jolts were smeared out over time, and disproves Tony's hypothesis that the upper section collided so solidly with the lower section that there was only one big jolt.

Had MacQueen and Szamboti graphed their data properly, that would have been obvious.
 
Tony Szamboti said:
I am saying the deceleration required to amplify the insufficient static load above, so that it can demolish the columns below, needs to be significantly greater than 32.2 ft/sec^2.

There needs to be a higher force than the static weight to break the columns and the only thing that can change is the deceleration as the mass is constant.

You apparently didn't understand as it seems has been the problem with a number of others. I would be careful who I called silly until I was sure I understood what was being said.
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Yes sir Tony!

lol, all kidding aside I'm just pointing out you've really got to get a grip on your terminology if you want to be taken seriously.
 
Tony Szamboti said:
I can prove what I am saying. Can you?
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Simple logic. The towers were designed to sway in the wind. The buildings that were brought down by verinage were not.

The buildings demolished by verinage had bearing columns pretty much evenly-distributed across all floors. The towers had columns around the outside and clumped together in the middle. The towers had expansive free-span steel truss floors. These are remarkable fragile, especially if compromised by fire, as compared to the more conventional croncrete slab floor, or to steel-truss floors with less free-span area.

No buildings in the world had more free-span floor trusses than the towers.

What happens to the columns after initiation of collapse is irrelevant. The only way they acted from that point onward may have had to do exclusively with the perimeter columns' acting as levers to more quickly break lower floor seats as the columns were pushed outward by the growing volumn of debris inside the tube.

The core columns below the point of failure just stood there doing nothing until a mechanical resonnance (observable in the spires of the north tower) shook them to pieces following the collapse of the floors that had held them upright.

Once collapse was initiated, the only important calculation is the weight needed to break the floors. The evidence suggests that some floor slabs failed prior to collapse initiation, and initiation of collapse added to the excess static load and dynamic load of rubble on the yet-unbroken slabs.

So, to make your figures worth something, you need to confine your examination to how muich energy was available and needed to break the floor slabs.
 
W.D.Clinger said:
Regarding my reference to one of his posts on the first page of this thread, Dave Rogers wrote:

They may have removed the smoothing function from the prose, but they left the misleadingly smoothed data in Figures 2, 3, 4, 5, and 6. Until you posted the above, I had assumed your earlier post was referring to the smoothing evident in those figures. I guess the early draft you saw had discussed the smoothing in the text of the paper as well, which would have been less misleading than what they actually published.

Here is Figure 5 from their paper:

[qimg]http://www.ccs.neu.edu/home/will/Music/Jokes/Szamboti/figure5original.jpg[/qimg]

Although Figure 5 above claims to present "actual measured velocity", that is a lie. Here are the actual measured velocities, as computed directly from their unsmoothed data in the table on pages 6-7:

[qimg]http://www.ccs.neu.edu/home/will/Music/Jokes/Szamboti/figure5honest.jpg[/qimg]

Their sampling rate was only 6 Hz, and their sampling error for distances was at least the 0.88 foot distance corresponding to a single pixel, so their sampling error for velocities is at least 5.28 ft/sec. That is also the quantum for their velocity measurements. A horizontal interval of 1/6 second doesn't mean anything unless the velocity measured for the following 1/6 second increases by two quanta or more (10.56 ft/sec).

As can be seen from the unsmoothed data in my graph, there appear to have been three mild jolts around 1.00, 1.33, and 1.67 seconds. Tony's expected delta-V of 13.13 ft/sec is shown in the dashed line, followed by the subsequent 1g acceleration implied by their model (instead of the incorrect reduced acceleration shown in their Figures 5 and 6, which was also incorrectly labelled as "reduced velocity"). If you compare the solid and dashed lines at 2 seconds, you will see that the sum of the three (or more) mild jolts was equal to Tony's expected jolt to within quantization error.

Hence jolts summing to the magnitude Tony expected have been there in his data all along, but Tony's expected big jolt was divided into at least three smaller jolts. That confirms the consensus hypothesis that the jolts were smeared out over time, and disproves Tony's hypothesis that the upper section collided so solidly with the lower section that there was only one big jolt.

Had MacQueen and Szamboti graphed their data properly, that would have been obvious.
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Your graph is based on the error being in favor of your position all the time, which is statisically improbable. Additionally, the error would not be an entire pixel or 0.88 feet but half of that.

This is a bogus use of the data you are showing here.

We also did not conclude there was no jolt simply because it wasn't obvious on the graph but because there was no velocity loss commensurate with the energy dissipation that would have occurred. Your bogus distortion of the data in an attempt to show some sort of step still can't eliminate that anomaly.
 
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Tony Szamboti said:
The modulus of elasticity of steel is approximately seven times that of concrete. I would bet you didn't know that.
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You are still not making sense here. Are you, as suggested by other posters, trying to convince us that concrete is more flexible than steel?:boggled:
 
leftysergeant said:
Simple logic. The towers were designed to sway in the wind. The buildings that were brought down by verinage were not.

The buildings demolished by verinage had bearing columns pretty much evenly-distributed across all floors. The towers had columns around the outside and clumped together in the middle. The towers had expansive free-span steel truss floors. These are remarkable fragile, especially if compromised by fire, as compared to the more conventional croncrete slab floor, or to steel-truss floors with less free-span area.

No buildings in the world had more free-span floor trusses than the towers.

What happens to the columns after initiation of collapse is irrelevant. The only way they acted from that point onward may have had to do exclusively with the perimeter columns' acting as levers to more quickly break lower floor seats as the columns were pushed outward by the growing volumn of debris inside the tube.

The core columns below the point of failure just stood there doing nothing until a mechanical resonnance (observable in the spires of the north tower) shook them to pieces following the collapse of the floors that had held them upright.

Once collapse was initiated, the only important calculation is the weight needed to break the floors. The evidence suggests that some floor slabs failed prior to collapse initiation, and initiation of collapse added to the excess static load and dynamic load of rubble on the yet-unbroken slabs.

So, to make your figures worth something, you need to confine your examination to how muich energy was available and needed to break the floor slabs.
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Sorry, but the analysis proves your simple logic wrong.
 
leftysergeant said:
You are still not making sense here. Are you, as suggested by other posters, trying to convince us that concrete is more flexible than steel?:boggled:
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No, but it will deform more per unit stress than steel. That is what the modulus of elasticity is a measure of.

The axial stiffness of a column is a function of modulus of elasticity, cross sectional area, and length.

Don't take my word for it look it up.
 
Tony Szamboti said:
Sorry, but the analysis proves your simple logic wrong.
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Why do any columns below the initiation point need to be crushed by vertical forces to produce the effects seen? We see perimeter columns being forced outward by the expansion of the rubble pile, we see floor slabs falling on each other, and we see the core slowly discombobulating by some means far, far behind the collapsing front. We do not see columns below the point of failure being crushed by a vertical force. Thus, we must conclude that the force driving the collapse is applied almost exclusively to the floor connectors and the slabs.

The energy budget to do this work is far smaller than that which would crush the columns downward.
 
Tony Szamboti said:
Your graph is based on the error being in favor of your position all the time, which is statisically improbable.
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:dl:

The velocities shown in my graph are taken straight from your table of unsmoothed position data. Subtract the position for time t-1/6 second from the position for time t, multiply by 6, and that's the velocity shown for time t in the graph. Anyone can check that for themselves.

Tony Szamboti said:
Additionally, the error would not be an entire pixel or 0.88 feet but half of that.
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The error is plus or minus one-half pixel, so the total error bar is one pixel, 0.88 feet, exactly as stated in my post.

Tony Szamboti said:
We also did not conclude there was no jolt simply because it wasn't obvious on the graph but because there was no velocity loss commensurate with the energy dissipation that would have occurred. Your bogus distortion of the data in an attempt to show some sort of step still can't eliminate that anomaly.
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And you can't even explain it properly. My graph shows the delta-V you expected near the end of the first second, and it also shows (to within quantization error) that the delta-V you expected was indeed seen between the end of the first second and the end of the second.
:popcorn1
 
W.D.Clinger said:
The velocities shown in my graph are taken straight from your table of unsmoothed position data. Subtract the position for time t-1/6 second from the position for time t, multiply by 6, and that's the velocity shown for time t in the graph. Anyone can check that for themselves.
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The data does not show where the velocity drops at a later point at any time, yet your graph does, so it is not using the data from the Missing Jolt paper.

The error is plus or minus one-half pixel, so the total error bar is one pixel, 0.88 feet, exactly as stated in my post.
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The error can only be 0.44 feet. You can't have a 0.88 error so you are wrong here too.


And you can't even explain it properly. My graph shows the delta-V you expected near the end of the first second, and it also shows (to within quantization error) that the delta-V you expected was indeed seen between the end of the first second and the end of the second.
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It is hard to even understand what you are trying to say here so it seems like you have a lot of audacity saying I can't explain something properly.
 
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Tony Szamboti said:
The data does not show where the velocity drops at a later point at any time, yet your graph does, so it is not using the data from the Missing Jolt paper.
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:dl:

You can't even read your own paper?

The numbers in the relevant part of your table beginning on page 6 are shown below. The first number in each row is from the last column (time in seconds), and the second is from the fifth column (distance in feet).

1.50 25.52
1.67 32.56
1.83 38.72

32.56 - 25.52 = 7.04 (that's 1/6 the velocity graphed at 1.67 seconds)
38.72 - 32.56 = 6.16 (that's 1/6 the velocity graphed at 1.83 seconds)

Hence the distance travelled between 1.67 and 1.83 seconds was less than the distance travelled between 1.50 and 1.67 seconds. Multiplying by 6 gives the velocities measured for those intervals. That's a drop in velocity, Tony. Those velocities are shown in my graph. They're from your own data.
 
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BasqueArch said:
There are many reasons why 3bodyproblem, for example, wouldn't post his real name on the net.
He could be a Dubai prince, or an employee of AE911Truth.

And where would that leave him. Mmmm?
In Dubai you can be caned 20 times for removing your veil of anonymity in the public sphere.

Besides, all the crazy ones are on the other side.
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The Dubai reference is a bit off... but close enough. (remember I live right down the road).

But then again, I post on several other discussion boards and if my identity were known, I'd get fired because of the things I have said about my employer. (again, I dont' live in the US nor work there. My employer often frequents discussion boards, and if my identity came out, I'd be on the next plane out of here because I am a "whistleblower.")

Generally in dubai they don't care removing the veil from a woman if she chooses to... but then again, her husband might say some other things about it.
 
I still do not see why it is neccessary to prove that enough energy was available to crush any column below the point of failure. It should be abundantly clear that all that needs to break to propogate a cascading failure are the floors and their seats in the perimeter columns. We see the perimeter columns peeling off in undamaged slabs and the cores still standing there shaking themselves to pieces behind the collapse front.
 
Tony Szamboti said:
The structure of the towers was more than stiff enough to transmit the deceleration to the roofline. In fact, it was probably stiffer than the Verinage buildings which all show a deceleration.
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Tony, can you please show a time measurement in a verinage demolition where the top falls tilted, as I asked you in message #1112?

Because unless you do, your argument by comparison to verinage demolitions is a straw man since they are made to fall without any tilt whatsoever. Have you read the verinage patent? I have.

Remember, my full name is Pedro Gimeno Fortea, if that matters to you. You can look it up in my profile now in case you forget.
 
pgimeno said:
Tony, can you please show a time measurement in a verinage demolition where the top falls tilted, as I asked you in message #1112?

Because unless you do, your argument by comparison to verinage demolitions is a straw man since they are made to fall without any tilt whatsoever. Have you read the verinage patent? I have.

Remember, my full name is Pedro Gimeno Fortea, if that matters to you. You can look it up in my profile now in case you forget.
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Pedro, the real fallacy is that a tilt would obviate a need for a jolt in a purely gravity driven collapse. The energy dissipation happens much too quickly to allow the continued drop to compensate for lost velocity.

I'll see if someone has the data for the building you show.

If you are capable why don't you measure the fall of the upper section of this building?
 
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Tony,

I PMed tfk my e-mail address (and I now have his). I don't know how you two want to proceed. Let me know.
 
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Tony Szamboti said:
Pedro, the real fallacy is that a tilt would obviate a need for a jolt in a purely gravity driven collapse. The energy dissipation happens much too quickly to allow the continued drop to compensate for lost velocity.

I'll see if someone has the data for the building you show.

If you are capable why don't you measure the fall of the upper section of this building?
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I see you edited this from "strawman". The irony of course is that the real strawman is the notion that the tilt would "obviate" the jolt.

I don't think anyone said there would be no jolt. What's been pointed out (numerous times) is that the tilt, among other things, would seriously reduce any measurable "jolt". If it could be measured at all.

This is of course confirmed by the evidence, as there is no "31g" jolt measured.

You have to be this tall to ride the Merry Go Round.
 
3bodyproblem said:
I see you edited this from "strawman". The irony of course is that the real strawman is the notion that the tilt would "obviate" the jolt.

I don't think anyone said there would be no jolt. What's been pointed out (numerous times) is that the tilt, among other things, would seriously reduce any measurable "jolt". If it could be measured at all.

This is of course confirmed by the evidence, as there is no "31g" jolt measured.

You have to be this tall to ride the Merry Go Round.
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Can you show calculations to support what you are saying?

We have measured the actual tilt and drop now and the collisions of the core columns occur in less about 250 milliseconds and this alone does not allow the continued fall to compensate for the velocity loss. If the east and west walls are added it gets worse. A significant velocity loss should have been observable in a natural collapse with the actual tilt observed.
 
Tony Szamboti said:
Pedro, the real fallacy is that a tilt would obviate a need for a jolt in a purely gravity driven collapse. The energy dissipation happens much too quickly to allow the continued drop to compensate for lost velocity.
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Maybe I'm having difficulties with the language because English is not my mother tongue, but isn't that precisely what I'm saying is a fallacy in *your* argument?

As I understand your sentence, you're saying that with a tilt there would be no noticeable jolt. That's also what I'm saying. Would you please explain?

ETA: Sorry, not exactly what I'm saying. What I'm saying is that you failed to take that factor into account when comparing jolts in fall speed for WTC and verinage demolitions.
 
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Tony Szamboti said:
Can you show calculations to support what you are saying?

We have measured the actual tilt and drop now and the collisions of the core columns occur in less about 250 milliseconds and this alone does not allow the continued fall to compensate for the velocity loss. If the east and west walls are added it gets worse. A significant velocity loss should have been observable in a natural collapse with the actual tilt observed.
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What calculations do you want? Link me to some numbers, I'll crunch some for you. Maybe I should check out GU's site and see what's going on there. Honestly though I thought Newton's Bit covered most of this already. This is just a rehash of what Gordon Ross claimed 3 or 4 years ago (although I believe he used 200 milliseconds, go figure).

Newton's Bit says: "The columns themselves can only resist a certain force, and cannot transfer anymore than that to the lower levels. The sum of the forces in the vertical direction is not equal to zero as this object is not at rest. If you wish to actually analyze what the force in the columns are, you can take the balance of kinetic, potential and strain energy over the initial axial displacement of the column (neglecting out of plane displacements due to the initial effects of buckling). You can determine the actual deacceleration of the block imposed by the columns in that case and what the actual force on the entire structure was."

As far as I'm concerned he's the one you really need to be talking to on this issue. Unfortunately he's tried, you won't listen, and now you're on your own. You've proven to be a waste of time to the big dogs Tony Szamboti. Most of this is really just going through the motions in case somebody new cares. I'm mildly interested because I just took a strength of materials course and it's fresh in my mind.
 
Tony Szamboti said:
I am saying the deceleration required to amplify the insufficient static load above, so that it can demolish the columns below, needs to be significantly greater than 32.2 ft/sec^2.

There needs to be a higher force than the static weight to break the columns and the only thing that can change is the deceleration as the mass is constant.

You apparently didn't understand as it seems has been the problem with a number of others. I would be careful who I called silly until I was sure I understood what was being said.
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Seriously? Do you really not understand that any deceleration of the upper block is already an application of a force opposing gravity of a magnitude greater than g? Maybe you're just sloppy with your application of terminology, but it seems you're missing some fundamental concepts here. This is, of course, made moot by the tilt anyway.
 
3bodyproblem said:
I see you edited this from "strawman". The irony of course is that the real strawman is the notion that the tilt would "obviate" the jolt.
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That's not entirely a strawman, since that's the word I used on the DU board when I attempted to explain to Tony why a tilt would mean that the upper block could no longer act uniformly on all the lower columns at once. (I won't post the graphic again since Tony's ability to ignore it is firmly established.) If the force of the falling upper block were applied to only a subset of the columns at any one time, then there might not ever have been a time that the columns being crushed could have supported even the static weight of the upper block, much less the (highly exaggerated) five-times reserve that Tony assumes. If that were the case, then no "load amplification" would be necessary to crush the columns sequentially, and no deceleration would be observed because there wouldn't be any time when there was enough resistance to cause deceleration. That is what I meant when I said that a tilt would obviate any need for a "jolt," and since Tony seems determined to dodge that argument rather than explain where it's wrong, I'm not much impressed with his changing "strawman" to "fallacy."
 
WTCs. In order for the top moving columns to fall they must first bypass the lower stationary columns. Upper moving column buckles to one side, breaks once and continues the fall to one side of the lower stationary column. Top column hits slab below, there are no other columns directly below. At no point are there two undamaged top/bottom column ends separated by 12 feet of air.
 
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Tony,

I finally got a chance to go thru your "Missing Jolt" paper with a little attention.

I'll refrain comment for the moment...

To the heart of the matter. Which I am pretty damn certain that multiple other posters have already pointed out to you.

Your assumptions for the "energy dissipation" (and then, by CoE & CoM, "loss of velocity") due to the impact of the 99th floor onto the 97th in your Appendix D are:

1) Uniform elastic spring action compression in the core and perimeter columns.
2) Compressive plastic yielding of core and perimeter columns in columns of the 97th and
99th stories.
3) Plastic hinging action (buckling) of all columns, in the two stories.

Here is my response:

A. You do realize, of course, that an INVIOLATE REQUIREMENT for 1) & 2) to be true is that the vast majority of the kinetic energy of the 1 story fall has to be transmitted from the upper block's columns to the lower block's columns. If that energy is NOT transmitted into the columns, then they will absorb none of it.

With me so far?

B. Further, you do realize, don't you, that in order for the energy of the fall to be transmitted into those columns, the vast majority of the columns MUST strike each other in such a way that enormous amounts of energy must be transmitted thru the interface between the impacting columns.

Agreed?
___

Now it's time for both of us to put our cards on the table & state CLEARLY our belief in the failure modes that lead to the collapse.

And, most specifically, how the failure mode(s) allows or disallows an interface between the upper columns & lower columns that is capable of transmitting that enormous energy.

Please do not dodge providing your explanation.

Unless you provide a clear, viable mechanism, you have no credibility to produce any analysis of the collapse.

In the interest of fairness, I'll go first.

My definition of "external columns units" or "assemblies" is the 3 story high, 3 column wide plus 3 spandrel welded units in which they were prefabbed.

Observation:
From the videos of the collapse, it is evident that at the instant that the collapse began, the external columns flexed and detached from the side of the building in 1, 2, 3 assembly units (i.e., 3, 6, 9 story high) "sheets". These assemblies had separated from all the trusses to the core and at most joints between the assemblies. They were flung mostly outward, some inward, some downward.

(Aside: It actually looked quite a bit like the start of a "slab avalanche".)

The external columns:
The assemblies flung outward were NOT buckled visibly, but were probably buckled in an engineering sense: to the point that they became unstable & could not carry their load. Therefore, it is evident to me that the failure mode for the external columns was a) buckling columns leading immediately to fractured connectors or b) fractured connectors alone. My money's on b), but the couple millisecond difference is irrelevant.

The core columns:
The core columns had much lower bending loads than the external ones (which were much further from the "neutral axis" of the bend), and had stronger core column-to-core column lateral bracing.

For the collapse initiation, my opinion is that there were 6 story buckles centered on the 98th floor, reaching upwards & downwards about 3 stories. Lateral loads pushed the middle knuckles to one side, and two more knuckles forming at the top & bottom of those columns.

For the collapse progression (not important for this conversation), my bet is that the failure mode was "shearing of the bolts & welds of the cross beams by falling debris, lateral displacement of the tops of the beams by the debris, and then snapping off of the beams at each successive interface again from the levering action of the falling debris acting on the free-standing column.)

My conclusions: It is impossible for any column to column contact at 1 story. I firmly believe that there was never anything other than a glancing contact at any time during the descent. Therefore vast majority (90+%) of the energy of the upper block was NEVER be transmitted to the lower columns.

Therefore there was never be a significant jolt. Just a large number of small ones.

My premise: No interface = no "jolt".
My proximate conclusion: There is no possibility of an interface.
My ultimate conclusion: "No jolt".

That's my judgment. You're welcome to comment on it. But it is not necessary to do so to justify your paper.
___

So, from my perspective, this is exactly what is lacking in your thesis:

Please provide some REASONABLE mechanism for the dynamic loads of the falling upper story to be transmitted from the upper framework into the lower framework thru some as-yet-undefined upper column to lower column interface.

Please describe that interface.

A sketch would be helpful.

Note well, please. I don't particularly care about BZ.

I want to know YOUR proposal for that interface between the upper columns & lower columns that would be capable of transmitting this enormous amount of energy.


Tom

PS. Once you've answered this question, I'll be happy to provide you with my critique of the rest of your paper.
 
Tony Szamboti said:
The error can only be 0.44 feet. You can't have a 0.88 error so you are wrong here too.
Click to expand...

DGM said:
Tony:
Can you explain how this can be with a single pixel equal to .88 feet?
Anyone else?
Click to expand...

Does ANYBODY believe that he can specify the vertical location of the roof within 5" with a video camera? At that distance?

If so, step right up. I've got a barely-used-bridge sale...


Tom
 
tfk said:
Does ANYBODY believe that he can specify the vertical location of the roof within 5" with a video camera? At that distance?

If so, step right up. I've got a barely-used-bridge sale...


Tom
Click to expand...
[edit] Depends--is the pixel "on" of "off"? [/edit]

You mean you don't use .001 inch precision with data accurate to 1 inch?
What's the world coming to?
.88 foot, indeed.
(Somebody on an airplane I did feathers analysis for required that the aileron hinges be placed to .0005 inch. The distance between the hinges in question? 96 inches.
Yeah, uh,huh...)
 
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