Merged Applicability of Bazant's model to the real world

[Newtons Bit]

When two objects of the same hardness impact on a small area, which cannot sustain the load, there will be local deformation, which will spread the load. Knives only work on objects which are softer than they are.

It does not just spread the load and then everything is magically okay. If the bearing capacity is exceeded it will deform. If the bearing capacity based on rupture stress is exceeded it will tear. The commentary in AISC acknowledges this.

After the local deformation a load amplification would be needed to go any further. Your explanation is the one that does some hand waving to proceed and to get a small contact area, as the small tilt would not cause that much misalignment.

I'm not the one hand waiving. The bearing surfaces between the columns is tiny. You cannot ignore this. It's just one more nail in "the missing jolt" coffin.

If you think your explanation has some merit show some calculations for how it could proceed without a need for load amplification, and how you would get such a small contact area to begin with.

Rn = 1.8FyAb [AISC 13th, J7-1]

Ab = 1

Rn << FyAg

For how the small contact area works, SEE THE PICTURES THAT WERE ALREADY POSTED.

 

[Edx]

Knives only work on objects which are softer than they are.
.

Maybe I am misunderstanding... but surely this depends on what speed the knife is travelling when it impacts the material, doesn't? Or are you going to be one of these people that thinks aluminium planes shouldn't be able to penetrate a steel building?

 

[Grizzly Bear]

Maybe I am misunderstanding... but surely this depends on what speed the knife is travelling when it impacts the material, doesn't? Or are you going to be one of these people that thinks aluminium planes shouldn't be able to penetrate a steel building?

Materiality is relatively unimportant compared with:
Mass
Force
Eccentricity of force
Distribution of force (intersects with eccentricity)
Ability to absorb impact shock

They do after all cut steel with highly concentrated blasts of water:

 

[R.Mackey]

It does not just spread the load and then everything is magically okay. If the bearing capacity is exceeded it will deform. If the bearing capacity based on rupture stress is exceeded it will tear. The commentary in AISC acknowledges this.

Better you than me talking to that brick wall...

Out of all the stupid things Tony's posted, this is up there with the worst of them.

 

[Newtons Bit]

Better you than me talking to that brick wall...

Out of all the stupid things Tony's posted, this is up there with the worst of them.

That one is bad, I'm more flabbergasted that he thinks I need to prove that the columns would be offset by at least 2", however. His perfect undamaged columns with perfect axial impacts delusion is mind boggling.

 

[ozeco41]

That one is bad, I'm more flabbergasted that he thinks I need to prove that the columns would be offset by at least 2", however. His perfect undamaged columns with perfect axial impacts delusion is mind boggling.

He has an artificially limited view of what happened and that view designed to support "missing jolt" at any cost to reality.

Others here have been down the track with Tony many times. These recent interactions have shown me that he seems to have no real in depth understanding of the mechanisms involved in WTC Twin Towers collapse on 9/11. Plus a stonewalling resistance to any form of reasoned discussion.

 

[Tony Szamboti]

That one is bad, I'm more flabbergasted that he thinks I need to prove that the columns would be offset by at least 2", however. His perfect undamaged columns with perfect axial impacts delusion is mind boggling.

What is mind boggling is your posting that the contact area would only be about 1% and now you are saying that I was contesting you saying they would be misaligned by 2".

Either you are confused or playing a little game.

I was contesting your 1% claim and 2" of misalignment on 17" wide core columns won't remove 99% of the contact.

 

[Tony Szamboti]

He has an artificially limited view of what happened and that view designed to support "missing jolt" at any cost to reality.

Others here have been down the track with Tony many times. These recent interactions have shown me that he seems to have no real in depth understanding of the mechanisms involved in WTC Twin Towers collapse on 9/11. Plus a stonewalling resistance to any form of reasoned discussion.

I would gladly listen to a rational argument that was backed by observation and science. However, you and the others here who have tried to say the columns missed each other or only had a small contact area have no observational basis for what you are saying.

Ryan Mackey was proven to be totally wrong when he tried to say the upper section of WTC 1 tilted 8 degrees before it descended and that this had caused the columns to miss each other and land on the floors. The measurements show the tilt was no more than 1 degree when the building strated to descend and the geometry shows that the columns could not possibly miss each other.

 

[femr2]

You and the others here who have tried to say the columns missed each other or only had a small contact area have no observational basis for what you are saying.

What is your observational basis for saying otherwise ?

ETA: (Wish you'd finish posts before hitting submit Tony)

The measurements show the tilt was no more than 1 degree when the building strated to descend and the geometry shows that the columns could not possibly miss each other.

The geometry of a perfect rigid body is guaranteed to be far from the actual geometry.

Can you REALLY suggest that deformation of a couple of inches was NOT present ?

I can probably show you deformation of the entire upper section greater than that...but regardless, it is simply unreasonable to suggest there wasn't, for so many reasons. Imagine the tension in the thing being let loose when the upper section becomes separated from the lower (by whatever means). How you rekn alignment was kept inch perfect afterwards Tony (after failure, or explosives, or deliberate displacement, or...) ?

 

[tsig]

I think most rational people would call your reply here incoherent. You seem to use that word loosely, much like your silly attempts at explaining the lack of deceleration of the upper section of WTC 1 as being possible in a natural collapse.

It is actually a joke that anyone technical who has looked into the technical aspects of Sept. 11, 2001, and is even a little bit aware of politics, can come away with any conclusion other than it was a shock and awe ruse to get the people of the U.S. to support the use of their military for pre-planned illicit oil wars.

On top of the evidence for controlled demolition, there is so much evidence for motive by insiders, with things like the PNAC manifesto, Dick Cheney's secret national energy policy meetings, and the Bush administration's lies about WMD in Iraq etc. that one has to make a concerted effort to ignore it and keep believing it was all fortuitously caused by evil terrorists from an area that these people wanted some control over.

Tony, in the hilited section the first half does not belong with the second half.

Your ideology is showing.

 

[Grizzly Bear]

[qimg]http://femr2.ucoz.com/_ph/1/2/428301377.jpg[/qimg]
Few inches.

Just because I think it bears repeating... Also applicable to the box columns the made up the exterior and core columns. When aligned the contact area spreads the load across the entire cross-section of the column. Start misalignment and then you introduce eccentricity, in addition to reducing the cross-section area which directly bears the brunt of the load on top of it. I don't see the problem with this...

The Bazant model as has been said a billion times already is just that... an optimistic model. Trying act like there's perfect end to end impacts and full use of the building's structural integrity is unrealistic since the model was never intended for that purpose EVER. I seriously don't understand Szamboti's, et al... purpose of trying to apply that model literally...

 

[ozeco41]

...The Bazant model as has been said a billion times already is just that... an optimistic model...

One thing is for sure. Tony cannot claim that he has not been told. And that fact on its own kills his "Missing Jolt" hypothesis, before we even start to consider what really happened.

...Trying act like there's perfect end to end impacts and full use of the building's structural integrity is unrealistic since the model was never intended for that purpose EVER...

..the argument against Tony's nonsense is even stronger. It does not depend only on the limits of the model. The real world of what actually happened means that end for end contact was already absent for most columns once the top block started to fall. And any column that somehow still had end for end contact would immediately fail - resulting in a "mini jolt" if we want to describe what actually happened in Tony's terminology.

...I seriously don't understand Szamboti's, et al... purpose of trying to apply that model literally...

There are two possible reasons given that the "Missing Jolt" hypothesis may have been a genuine error when first written and published. It can no longer be a genuine error which leaves two alternates: 1) Tony simply does not understand the engineering involved despite multiple explanations from a range of perspectives; OR ) He does understand and is deliberately putting forward technical claims which he does not believe. It is not appropriate to offer an opinion as to which. But the most generous view is that he does not understand the fairly complex situation of the Twin Towers collapses and recent postings here lend strong support to that possibility.

 

[ozeco41]

I would gladly listen to a rational argument that was backed by observation and science. However, you and the others here who have tried to say the columns missed each other or only had a small contact area have no observational basis for what you are saying.

Hogwash again Tony. The fact that the top block was falling means no end for end contact transferring axial loads. your own "Missing Jolt" hypothesis relies on the validity of that claim which is observable evidence. You cannot use it to back your own nonsense and deny it to others. The only difference is that you take the no end for end contact to mean column bits removed by "unnatural causes" which raises two points:

• Ends bypassing is also a valid reason for no end for end contact and can be demonstrated in a number of ways.
• your pre-conceived need for "unnatural causes" has no termination point and, whether your idea is possible or not, that lack of a logical termination kills it dead.

...but, at this stage, how about you stop the repeated untruths that there is no observational evidence.

...The measurements show the tilt was no more than 1 degree when the building strated to descend and the geometry shows that the columns could not possibly miss each other.

...gawd here you go again. Who gives a damn what the geometry says. The forces available were orders of magnitude higher than needed to deflect any number of columns. PLUS the fact that the top block was falling proves that there was no end for end contact transferring significant load..... It is a very simple concept.

 

[Tony Szamboti]

Hogwash again Tony. The fact that the top block was falling means no end for end contact transferring axial loads. your own "Missing Jolt" hypothesis relies on the validity of that claim which is observable evidence. You cannot use it to back your own nonsense and deny it to others. The only difference is that you take the no end for end contact to mean column bits removed by "unnatural causes" which raises two points:

• Ends bypassing is also a valid reason for no end for end contact and can be demonstrated in a number of ways.
• your pre-conceived need for "unnatural causes" has no termination point and, whether your idea is possible or not, that lack of a logical termination kills it dead.

...but, at this stage, how about you stop the repeated untruths that there is no observational evidence.

...gawd here you go again. Who gives a damn what the geometry says. The forces available were orders of magnitude higher than needed to deflect any number of columns. PLUS the fact that the top block was falling proves that there was no end for end contact transferring significant load..... It is a very simple concept.

Your simple concept has no other example in any natural force caused collapse. All known examples of natural force caused collapses have deceleration.

There really is only one answer to why the upper section of WTC 1 does not decelerate and that is that the legs were being taken out from under it by unnatural forces. That is the truly simple concept that works and for which there are plenty of examples.

 

[Dave Rogers]

Your simple concept has no other example in any natural force caused collapse. All known examples of natural force caused collapses have deceleration.

Give some examples, apart from verinage, which has already been discussed.

Dave

 

[Newtons Bit]

What is mind boggling is your posting that the contact area would only be about 1% and now you are saying that I was contesting you saying they would be misaligned by 2".

Either you are confused or playing a little game.

I was contesting your 1% claim and 2" of misalignment on 17" wide core columns won't remove 99% of the contact.

Stop lying.

This is what you posted:

After the local deformation a load amplification would be needed to go any further. Your explanation is the one that does some hand waving to proceed and to get a small contact area, as the small tilt would not cause that much misalignment.

Lying liars aren't taken seriously, Tony Szamboti. I suggest you start arguing from a position of truth if you want to continue.

To address how one gets a 1% contact area, I suggest you first find the area of a 14x14x5/16 perimeter column (A = 17.5in²) and the area of the two contact points (A = 0.195 in²). If you're not sure what the contact surfaces are. Look at the picture I posted or the one that femr2 posted. Then divide the area of the contact points by the the area of the perimeter column. If your arithmetic is better than your ability to tell the truth, you should get about 1%.

Feel free to repeat the exercise for the core columns. I don't know what the exact size of the wide-flange columns were, but just for giggles I ran the numbers for the largest available wide-flange shape: W14x730. It has a contact area of about 4%.

WoOooOOooO

 

[Newtons Bit]

He has an artificially limited view of what happened and that view designed to support "missing jolt" at any cost to reality.

Others here have been down the track with Tony many times. These recent interactions have shown me that he seems to have no real in depth understanding of the mechanisms involved in WTC Twin Towers collapse on 9/11. Plus a stonewalling resistance to any form of reasoned discussion.

Oh I know. There's a huge list of impossible assumptions he makes to achieve a scenario where a jolt is possible. He knows it too. But this is the last rung he's got to hold on to. If he lets go of it, then he falls back into the world of the sane, and that's a very bright and painful world to be in after living for so long in the world of "Truth".

 

[femr2]

I don't know what the exact side of the wide-flange columns were

This image...

(click to enlarge)

...is from my core model, and uses the data from...

http://wtcmodel.wikidot.com/cc1002

The image is for CC 1002 for floor 98-100...

ETA: Might be 95-97, will check. Difference is trivial.

1.205*1.936*2 = ~4.67 in²
1.936*16.025*2+12.624*1.205 = ~77.26 in²
About 6% contact area for the offset image supplied.

 

[Newtons Bit]

I get about 6% for that one. I'm still convinced that the column would fail to develop anything close to entire compression capacity of the undamaged column.

 

[rwguinn]

It does not just spread the load and then everything is magically okay. If the bearing capacity is exceeded it will deform. If the bearing capacity based on rupture stress is exceeded it will tear. The commentary in AISC acknowledges this.

How does he think a cold chisel works?

I'm not the one hand waiving. The bearing surfaces between the columns is tiny. You cannot ignore this. It's just one more nail in "the missing jolt" coffin.



Rn = 1.8FyAb [AISC 13th, J7-1]

Ab = 1

Rn << FyAg

For how the small contact area works, SEE THE PICTURES THAT WERE ALREADY POSTED.