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you see if you want i can send you the three pdf's of Bazants papers from the 2002 one through to the 2007 one and would save you a lo of cutting and pasting....but it would be nice if you would try not to baffle people with it
can you do the differential equation for me.....I can
use your own eyes and look at the diagrams.....it is not hard..and i will make this very easy for people to understand ......and if you looked in the post i had put forward in which i was showing...it would help....how do you think i come to my conclusions.....it is through observation....now look at your own pastings.....you see the drawing of the examples of crush down....
I am sure you do...it is not all about the maths here as the maths become erroneous from the outset.
why is this the case...it is because when you look at the way Bazant is presenting this whole senario...it is, listen to this......Crucial...Absolutely crucial the upper block remain RIGID......IT CANNOT LOSE mass.
now if you looked at the frame by frame breakdown of the real world happening....mass was expelled....so right there the maths do not stand up...
Here V0 = initial volume of the tower, V1 volume of the rubble on the ground into which the whole tower mass has been compacted; (z) = effective compaction ratio = (1/h)× the thickness of the layer of debris to with each story is compacted; Kout = fraction of mass that is ejected outside the tower perimeter before it receives significant downward acceleration, and Wd(z) = total energy dissipation up to level z (for the idealized special case of = Fc = out = 0 and constant μ = dm/dz, Eq. (2) reduces to the differential equation (zz˙)˙ = gz, which was
The first error which Dr. Bazant has made is his assumption that all of the available
energy would be utilised exclusively in the destruction of the uppermost storey of the
lower section. This is physically impossible under any and all circumstances.
also keeping these things in mind.....at the point of the impact there will be a loss energy as the energy is transfered into the surounding structure...snapping of connectors...buckling of steel apparent compression of the core....which i think you failed to address from the video i showed....so again....this would cause a slowing of the falling object.......do we see that occuring....again look at my frame by frame analysis....the upper block which is no longer a rigid block continues at accelerating into the path of greatest resistance ....again...Explain
where Wd = energy dissipation per story due to buckling; Fb = energy per unit height consumed for buckling of steel columns; Fs = energy per unit height consumed by fragmenting (or comminuting) concrete floor slabs and core walls; Fa = energy of expelling air (laden with dust), per unit height.
According to Final Report on the Collapse of the World Trade Center Towers, the crushing front initiates at the 96th in the North Tower, and the 81st
story in the South Tower. The effective compaction ratio 0.18, as estimated in. The mass ejection ratio, out, is harder to estimate. A crude estimate can be based on the profile of the rubble pile after the collapse . Baˇzant and Verdure estimated that about 20% of the rubble volume resided outside the footprint of the tower, and so out 0.20.
do you see what is being said here....and if you just come back with more copying and pasting of the Bazant report...then that is not going to cut it as i think you need others whom back up the report also...since it is the report that is in dispute.
Nor is this deformation of the columns in the upper and lower sections limited to their elastic range. It must be noted that the columns in the upper section could not deliver a greater force than they themselves were able to transmit. In a situation where the columns in the upper section were asked to deliver loads at magnitudes sufficient to cause plastic deformation of columns in the lower section, then they themselves would simultaneously suffer plastic deformation at levels proportionate to their ability and applied loads.
During the crush-down phase, the moving upper part of tower (C in Fig. 1 bottom), with a compacted layer of debris at its bottom (zone B), is crushing the lower part (zone A) with little damage to itself, except before a thick enough layer B of debris forms).
Originally posted by Joey Canoli
reply to post by Drunkenparrot
The Ross paper is seriously flawed in 2 ways:
1- He uses the same limiting case as does Bazant does in his first 2002 paper on the subject. That is, he assumes that ALL the columns are being buckled/crushed/whatever all the way to the ground. That didn't happen.
It is undeniable that the core column "spire" that is seen in both collapses proves that not all the core columns were buckled/crushed/whatever. And it is undeniable that there are large sheets of ext columns falling outside the building during the collapse, and this proves that they weren't buckled/crushed/whatever either.
An object can store energy as the result of its position.
We assume a perfectly inelastic collision, so following the impact, the masses travel at the same velocity.
As momentum is conserved...
Pre-impact momentum (1*10+1*0) = Post-impact momentum (2*v)
...the post-impact velocity is 5 m/s
The pre-impact KE was (0.5*1*10^2) = 50 J
The post-impact KE is (0.5*2*5^2) = 25 J
Both masses are perfectly rigid, and so cannot deform.
There is no resistance.
Where did that 25 J go ?
The answer to what energy is "used" to crush the concrete is explained once truthers are able to understand just where that 25J went to......
Originally posted by ANOK
So you agree that Bazants paper is flawed also?
That was one column out of 47. Not even close to the majority of the steel. So no that is not evidence that most of the steel weren't buckled/crushed/whatever.
Why would the objects be traveling at the same velocity after impact because it was an inelastic collision?
You seem to misunderstand what momentum conservation is also. It does not mean objects maintain their momentum after collision, it means they will try to, but resistance stops this, and it is why objects are deformed.
If two objects with unequal mass collide, the one with the most mass will conserve its momentum better than the smaller mass, so the smaller mass will receive more deformation.
Yes there is. Whenever two objects come in contact you have resistance. Resistance is friction.
There is no 25J.
CONCLUSIONS
Dr. Bazant has stated in his analysis, that his energy ratio would be increased in the event
of early failure of the column end connections. This is correct and examination of the
debris pile with specific regard for the numbered and identifiable columns from the area
in and around the aircraft impact area could have given more precise information from a
physical rather than a theoretical source.
The short cut taken by NIST in relying upon this theoretical work, allowed them to avoid
a continuation of their examination to include the physical evidence available from the
collapse. Such a continuation would have shown many points of evidence which cannot
be readily explained by a collapse whose initiation and progression was caused as a result
of aircraft impact and subsequent fires. It does however allow the authors of the NIST report to pass responsibility to Dr. Bazant for this, the most important part of the
investigation.
A theory which can be so easily refuted is not an adequate foundation on which to
rest the conclusions of a report on an event with such far reaching global
consequences.
But since NIST relies upon the work of Dr. Bazant to justify their assertion that
collapse, once initiated, would inevitably progress to ground level, this refutation of
Dr. Bazant's work and theory also serves as a refutation of this most crucial part of
the NIST report.
This is physically impossible under any and all circumstances.
It is impossible for all of the energy of the falling section to act on only the one topmost storey in the lower section, since the very act of transmission of the energy to that storey, dictates that all of the storeys in the upper section will come under load and consume energy
Originally posted by ANOK
It would be good if you understood the physics.
Why would the objects be traveling at the same velocity after impact because it was an inelastic collision? Did you forget the equal and OPPOSITE reaction law?
Elastic and Inelastic Collisions
A perfectly elastic collision is defined as one in which there is no loss of kinetic energy in the collision.
An inelastic collision is one in which part of the kinetic energy is changed to some other form of energy in the collision. Any macroscopic collision between objects will convert some of the kinetic energy into internal energy and other forms of energy, so no large scale impacts are perfectly elastic.
Momentum is conserved in inelastic collisions, but one cannot track the kinetic energy through the collision since some of it is converted to other forms of energy. Collisions in ideal gases approach perfectly elastic collisions, as do scattering interactions of sub-atomic particles which are deflected by the electromagnetic force.
Some large-scale interactions like the slingshot type gravitational interactions between satellites and planets are perfectly elastic. Collisions between hard spheres may be nearly elastic, so it is useful to calculate the limiting case of an elastic collision.
The assumption of conservation of momentum as well as the conservation of kinetic energy makes possible the calculation of the final velocities in two-body collisions
The reaction is one of the least understood of the basic physical concepts, perhaps because it is often poorly taught or incorrectly described in many publications, including textbooks, or because Newton's laws of motion may appear counter-intuitive.
A modern statement of the third law of motion is
If a force acts upon a body, then an equal and opposite force must act upon the body that exerts the force.
It is essential to understand that the reaction applies to another body (the body that exerts the force) than the one on which the action applies.
For example, in the context of gravitation, when object A attracts object B (action), then object B simultaneously attracts object A, with the same intensity and an opposite direction.
The physical nature of the reaction is identical to that of the action. If the action is due to gravity, the reaction is also due to gravity.
A particularly subtle common mistake is to confuse the forces that cause action and reaction with the actual action and reaction.
Newton's third law is frequently stated in a simplistic but incomplete or incorrect manner through statements such as Action and reaction are equal and opposite To every action there is an equal and opposite reaction
These statements fail to make it clear that the action and reaction apply to different bodies. Also, it is not because two forces happen to be equal in magnitude and opposite in direction that they automatically form an action-reaction pair in the sense of Newton's Third Law
Originally posted by Joey Canoli
Where did that 25 J go ?
The answer to what energy is "used" to crush the concrete is explained once truthers are able to understand just where that 25J went to......
Originally posted by ANOK
There is no 25J.
Originally posted by Joey CanoliNope.
It is a perfectly acceptable bounding analysis.
Lie
Cuz that is the very definition of an inelastic collision.
Perfectly elastic collisions are those in which no kinetic energy is lost in the collision.
You are uninformed.
You are unable to understand the conditions of the problem as set forth.
resistance can take many forms, since resistance is just another way of saying a process that "uses up" ke.
Energy is always conserved.
It can't just disappear into the ether.
It had to go somewhere. Where?
I'll help you out a little here. The problem, as set out contains a glaring falsehood that is so simple that anyone should be able to see it after a cursory glance.
But you couldn't see it.
That says all I need to know about your knowledge of physics.
At this point, your hilarious responses must begin to give credence to the notion that there are indeed, disinfo agents on these types of message boards trying to make truthers appear as ignorant.
Perfectly elastic collisions are those in which no kinetic energy is lost in the collision.
Inelastic Collisions in One Dimension
In an inelastic collision, two (or sometimes more, but let's not get carried away) objects collide and stick together. We generally ignore any outside forces on the colliding objects, so the two-object system is an isolated system. This is reasonable in practice if we examine the objects during the time interval immediately before the collision and then immediately after - before friction, gravity, etc., have time to exert any appreciable impulses on our system.
Originally posted by ANOK
How is that a lie?
Originally posted by WarminIndy
Is it my imagination or is that an edited picture? Watch the bottom of the picture as it shows, the windows at the bottom are not lined up.
Originally posted by Joey Canoli
Originally posted by WarminIndy
f you listen to the evidence carefully enough, it will speak to you and tell you exactly what happened. If you don’t know what happened, keep listening to the evidence until you do. The evidence always tells the truth. The key is not to allow yourself to be distracted away from seeing what the evidence is telling you.
Empirical evidence is the truth that theory must mimic.
Originally posted by plube
Once again all i see that all you have done is pasted a whole bunch of things to baffle people with BS.....
Gordon Ross does not have a clear understanding of structural engineering, and this is evident in his paper. His idea of the concept of buckling is incorrect.
This in turn has led him to write a paper that completely over-exaggerates the structural capacity of the WTC towers and completely mislead a group of people who depended on him, as a professional engineer, to know what he was talking about. This is not his fault, or the fault of the education system which trained him.
He is not a structural engineer; these concepts are not readily available to him. Even I have made mistakes on this concept before. We all make mistakes. This is one that could probably be corrected. This, however, is not about mistakes.
Mr. Ross, your conclusions and sums and methods have been proven wrong. In my previous letter I offered you the chance to fix and update your calculations out of professional courtesy.
Out of respect for your abilities, I said it would be easy for you to do. I had hoped that you would take a harder look at that issue, and take another look at the rest of your paper, but you have chosen not to do so.
Your response was nothing more than, “fake but accurate”. This is a disgusting manner for any engineer to respond. Sir, retract your paper or fix your calculations.
The author of this work, Gordon Ross, was born in Dundee, Scotland. He holds degrees in both Mechanical and Manufacturing Engineering, graduating from Liverpool John Moores University, in 1984.
Liverpool John Moores University is a British 'modern' university located in the city of Liverpool, England. The university is named after John Moores and was previously called Liverpool Mechanics' School of Arts and later Liverpool Polytechnic before gaining university status in 1992, thus becoming Liverpool John Moores University
The programme has been designed with particular emphasis on advanced manufacturing technologies and the application of advanced materials...
...Skills, acquired during this programme, will allow graduates to make an immediate contribution to a company's capability and operation, and to ultimately progress into senior management positions
Originally posted by plube
reply to post by Drunkenparrot
...but nice try on the Bazant stuff....but i think you might want to reconsidered using the Bazant model as it is repeatedly getting torn to shreds.
also if you go to the JEM(journal of engineering and mechanics) you will find Bazant paper has been taking a beating and all these papers have been subjected to peer review.....
....so until they start to come back with reasonable responses to the papers presented for peer review i guess it would mean they are stumped...and cannot answer what has been put forward to them..
Originally posted by plube
....how do you think i come to my conclusions.....it is through observation....
...it is not all about the maths here as the maths become erroneous from the outset.
Originally posted by plube
Journal of Engineering Mechanics ASCE, in press
9/13/01, Expanded 9/22/01, Appendices 9/28/01)
Originally posted by TheMindWar
Shills are hard at work on ATS i see, and the poster of this thread os obviously one. I have 1500 architects and engineers backing me up, who have you got?
I suppose you are happy that the US was responsible for killing so many people including women and children. Mate, you obviously have some kind of mental disorder. You should seek help right away as you are probably a danger to the public. This is truely a sick and disturbed post and should be deleted.
I feel allowing this thread to continue degrades the lives lost on 9/11, which is obviously what OP is trying to do.
Sick.
Originally posted by plube
Once again all i see that all you have done is pasted a whole bunch of things to baffle people with BS....It is very impressive indeed...and then you also try to slander Gordon Ross...with how great Bazant is in his accolades....and the rest of people are to be discredited...
well i attended Gordon ross' presentation in London...and it is very informative...and explanatory....
His credentials are very creditble...so please do not go down the road of saying how great Bazant is while discrediting others.....I have said Bazant is highly regarded in his field...but as i have said...If one works with erroneous data ones whole report fails.....
I completely understand what Bazant is trying to get across with the leading debris field progressing down the collapse....and the rigid upper section would just follow the path of destruction...but this is not what the observed was,was it.
You have not yet once explained why the upper section is collapsing on itself before the lower section crushes down...even taking into account the leading debris.....I can see you are still trying to baffle people with this theory of Bažant's......just Explain in your OWN words.....Why the upper section collapses first.....this is the most important Item that is required for Any of Bazants work to be Valid in his analysis.
Why the upper section collapses first.....this is the most important Item that is required for Any of Bazants work to be Valid in his analysis.
I have more respect fot this man than Bazant...who has not yet publicly come forward to dispute any claims against him....he does not answer his Emails...he does not come forward with rebuttles and he condescends people for their responses and says they only need to go back to school....that is someone whom hides and he will NOT come out and be publicly debated....I have asked him too.
You know why he wont....because he cannot back it up.
I do commend you on all your efforts here....but you have not answered any question...you have only tried to make others out be less intelligent in some stanege way through the use of crud.....
make (sic) others out be less intelligent in some stanege way through the use of crud
The core was yet again ignored in your presentation....you showed the floors and their truss seats.....which was not once what i was stating i said that the structure was 60% supported by the core...and 40% by the perimeter columns.....Did you adress that.....nope....in all the wonderful presentation you did address it......
I asked you to explain the collapse of the Upper RIGID block before progressive collapse of the Lower block.....did you address that.....nope.
All i see is the presentation of the wonderful Bazant.....so until you can actually provide answers to the questions i have about those two points.....How the core straight down collapses on itself........and how the upper collapses before impactin the lower block .
I personally cannot use the Bazant paper
as even in his own work it does not work....
it is theorectical that does not compliment the observed.