Outside energy had to be introduced for the twin towers to collapse the way they did

Originally posted by ANOK

Now let me hear you claim steel loses half it's strength at X temperature

Strawman.

NIST, nor Bazant don't claim that as the cause of collapse initiation.

Mod temp high load creep buckling is well supported by physical evidence and FEA analysis.

Unless you know what the safety factor of the steel components were, you have no idea at which point anything would become unstable.

It looks like the FOS can be anything, according to truther logic now.

Somewhere on this forum, ANOK was claiming it was necessary to know what the FOS was in order to calculate the potential energy of the tower section above the impact zones.

Aparently, FOS has now achieved super nano thermite status as being able to be used as an explanation for anything and everything....

If the building components as a whole had a safety factor of 2 (the minimum) what does that mean?

That if the loads were evenly distributed amongst the remaining columns, that 1/2 of them would need to be removed in order to initiate collapse.

But guess what? They weren't. NIST proved that, and you have zero logical rebuttal to their study. Incredulity just won't cut it, pal...

If the towers overall had an FoS of 2, then 50% loss of strength would not cause the towers to collapse. So working against your hypothesis is the fact that less than 20% of any steel in the towers was ever in contact with fire and never all at the same time, and the FoS would be much larger than 2 for a combination of components that each had an FoS 2 or greater.

If you don't know the FoS of the components you can make any claim you want, but it is as useful as knowing whether the toilets flushed when the planes hit.

Does that help you understand my point?

It helps everyone to understand your confusion.

You believe that after impacts, that the loads would be distributed evenly amongst the unaffected columns. This is false, especially with the off-center hit on 2.

It shows that you have zero understanding of how loads are not evenly distributed amongst the remaining columns, but rather, are distributed firstly to adjacent columns. And that high steel temps are not necessary to initiate collapse. Loads must be factored into it as well.

Indeed, Bazant explained this thoroughly:

www.civil.northwestern.edu...
"The decrease of yield stress upon heating depends
strongly on the rate of loading or on its duration, and is
properly described as time-dependent flow, or viscoplastic
deformation. For 1 hour of loading, the decrease is much
greater than it is for the typical duration of laboratory tests of
strength, which is of the order of 1 minute. In columns, the
flow leads to time-dependent buckling, which is in mechanics
called viscoplastic buckling or creep buckling. A temperature
rise to 250°C at high stress level can greatly shorten the
critical time t* of creep buckling.
Some critics do not understand the enormous destabilization
potential of creep buckling. The Dorn-Weertmann
relation indicates that
˙ =Ane−Q/kT
where
˙ =strain rate;
A=constant; n5; Q=activation energy of interatomic
bonds; and k=Boltzmann constant; Hayden et al. 1965,
Eq. 6.8; Courtney 2000; Cottrell 1964; Rabotnov 1966. According
to Choudhary et al.
1999, the typical value of Q/k
for ferritic steel alloys is about 10,000°K
and about
20,000°K according to Frost and Ashby 1982. Using
10,000°K, one may estimate that, upon heating from 25°C

T0=298°K to 250°C
T=523°K, the rate of deformations
attributable to dislocation movements increases about 106
times, and more than that when using 20,000°K. For heating
to 150°C, the rate increases about 104 times. This rate is
what controls the rate of flow and, indirectly, the yield
strength upon heating.
Furthermore, the equations in the aforementioned sources
and those in Sec. 9.3 of Bažant and Cedolin
2003 make
it possible to calculate that raising the column load from
0.3Pt to 0.9Pt
where Pt=failure load=tangent modulus
load at temperature 250°C
T=523°K shortens the critical
time t* of creep buckling from 2,400 hours to about 1 hour

note the differences in terminology: material scientists distinguish
between the microstructural mechanisms of creep,
occurring at low stress, and of time-dependent flow, occurring
near the strength limit, whereas in structural mechanics,
the term creep buckling or viscoplastic buckling applies to
any time-dependent buckling regardless of microstructural
mechanism; thus the source of creep buckling of steel columns
at high stress is actually not creep, as known in materials
science, but time-dependent flow of heated steel at high
stress.
Recently reported fire tests
Zeng et al. 2003 have demonstrated
that structural steel columns under a sustained load
of about 70% of their cold strength collapse when heated to
250°C. However, creep of structural steel in the service
stress range begins only after the steel temperature rises
above 350°C
Cottrell 19

reply to post by Joey Canoli


Yes ANOK and the rest ignore things that cause them problems now he is preaching FOS makes a change from laws of motion, the thing is if HE actually knew how to apply the laws correctly he would see that the collapse caused loads way above the FOS!

Originally posted by wmd_2008
reply to post by Joey Canoli

 

Yes ANOK and the rest ignore things that cause them problems now he is preaching FOS makes a change from laws of motion, the thing is if HE actually knew how to apply the laws correctly he would see that the collapse caused loads way above the FOS!

So what was the FoS then? Do you know every component had an FoS, and when components are combined the overall FoS increases? That the FoS would be more lower in the core than the top? What pressure could the connections withstand before failure, combined?

I'm not missing anything, I am trying to make people realise YOU are missing something. Sorry if I ignore your other fantasies.

Go to this website...

What Happens When Two Things Collide

This selection will show you what happens when two objects crash into each other, or collide.

A collision between two objects involves two things: how much mass each object has, and how fast it is going when it entered the collision.

This page will allow you to set up your own crash movie by selecting different vehicles and speeds. Fasten your seat belt!

www.fearofphysics.com...

(Don't be afraid kiddies, it is not affiliated with the 'truther' movement in anyway, other than it also has nothing but facts, and tells the truth)

Do the most extreme test and see if you can make the smallest mass damage the largest mass without receiving more damage itself. Do it with equal masses and see what happens. You might learn something, but I doubt you would admit it somehow.

Do the test and then tell us the results, and then tell me what I'm missing and why you can't grasp that all collisions work the same way, and velocity does not work the way you claim.

C'mon prove me wrong, this is your chance...

Edit; I did this one...

The redtruck came into the collision at 0.00 meters per second (0.00 miles per hour)
It left moving at -0.01 meters per second (-0.03 miles per hour)

The scooter came into the collision at -40.23 meters per second (-90.00 miles per hour)
It left moving at 40.22 meters per second (89.97 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

The scooter was jolted backwards which means, when conservation of momentum is considered, the scooter would have received far more damage than the truck. I hope that is simple enough for you to understand, and isn't missing anything? It has your velocity and my mass, and Newtons three laws all working together, just as they should and always have. No amount of spin from you is going to change nature.

Don't fear the physics (we'll be able to fly).

Originally posted by bottleslingguy
reply to post by psikeyhackr

 

the loads were so unbalanced it would only have to WEAKEN one crucial section to tip the scales. You guys forget the buildings had substantial damage to the skin and core already, both being crucial elements of the design. It wouldn't take much to pass the tipping point towards total failure like the Titanic.

No one knows how much damage there was to the core in either building. That is all guesswork.

FEMA said the perimeter columns were operating at 20% of their load capacity. So even with all of the columns gone from one side of the building it should have stood.

But even if the collapse started there is no explanation for how it came down so fast. A magical collapse slowed by only the conservation of momentum with all levels have equal mass gives a 12 second collapse time. That is an easy computer simulation to do. So have to destroy supports must have slowed a real collapse down.

So why didn't it?

That is the problem the physics profession should have explained in 2002.

The south tower is a whole 'nuther story. How did 29 stories break loose and tilt/rotate 22 degrees?

The physicists need to run away from that. They don't even talk about the center of mass.

psik

reply to post by psikeyhackr

So have to destroy supports must have slowed a real collapse down....

By how much? An hour? A day? A week? Milliseconds? How long does it take for something to break under load?

Originally posted by hooper
reply to post by psikeyhackr

 

So have to destroy supports must have slowed a real collapse down....

By how much? An hour? A day? A week? Milliseconds? How long does it take for something to break under load?

I have provided a demonstration.



For the north tower there were more than 90 levels to be destroyed but only 15 coming down. Get the physics profession to explain why they don't even want to know the distributions of steel and concrete.

I say the collapse should have arrested if it even got started. And I don't think it should have within two hours.

psik

reply to post by psikeyhackr

I have provided a demonstration.

Where? All I see is that silly video of paper loops and washers stuck on a broomhandle. You have some kind of demonstration that is RELATIVE to the collapse of the WTC towers?

Also, can you answer the question - how much time should have been consumed by the failure of the columns? Was it hours, minutes, weeks, years? Millisceconds? Nanoseconds?

Also, how is it that you determined that the collapses were impossible without any of the information that you say is imperative to making a determination?

Originally posted by psikeyhackr

I have provided a demonstration.

Again, we both agree that your demonstration is not a close approximation of the towers' structure or collapse, so why do you insist on posting it as if it is evidence one way or the other?

Originally posted by DrEugeneFixer

Originally posted by psikeyhackr

I have provided a demonstration.

Again, we both agree that your demonstration is not a close approximation of the towers' structure or collapse, so why do you insist on posting it as if it is evidence one way or the other?

I never claimed it was an approximation of the structure of the tower. I said it was a gravitational collapse of a self supporting structure where energy had to be expended to damage the supports. Where has anyone built one that can completely collapse? You people can't even specify the distributions of steel and concrete in the towers.

At least I can make my supports as weak as possible. Buildings are not made that way.

So all you have is TALK! Very impressive.

psik

So no takers huh?

No one jumping all over this post huh?

Afraid of the physics huh?

www.fearofphysics.com...

Here are two objects of the same mass hitting each other at the same velocity...

The redtruck came into the collision at 40.23 meters per second (90.00 miles per hour)
It left moving at -40.23 meters per second (-90.00 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

The redtruck came into the collision at -40.23 meters per second (-90.00 miles per hour)
It left moving at 40.23 meters per second (90.00 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

Both objects reacted equally in the collision, equal mass, equal result. Consider momentum conservation, and both trucks would receive more or less equal damage.

15 floors can not cause 95 floors to collapse, crush, whatever term you like.

Originally posted by ANOK

Both objects reacted equally in the collision, equal mass, equal result. Consider momentum conservation, and both trucks would receive more or less equal damage.

What's the point of this?

Originally posted by DrEugeneFixer

Originally posted by ANOK

Both objects reacted equally in the collision, equal mass, equal result. Consider momentum conservation, and both trucks would receive more or less equal damage.

What's the point of this?

He is trying, desperately, to imply that 15 floors can't "crush" 90 floors because, basically, 90 is a bigger number than 15. He would like you to infer from the posting that there is some relationship to 9/11 and two red trucks hitting each other at 90 mph. There isn't. But you probably know that.

Originally posted by ANOK
So no takers huh?

No one jumping all over this post huh?

Afraid of the physics huh?

www.fearofphysics.com...

Here are two objects of the same mass hitting each other at the same velocity...

The redtruck came into the collision at 40.23 meters per second (90.00 miles per hour)
It left moving at -40.23 meters per second (-90.00 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

The redtruck came into the collision at -40.23 meters per second (-90.00 miles per hour)
It left moving at 40.23 meters per second (90.00 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

Both objects reacted equally in the collision, equal mass, equal result. Consider momentum conservation, and both trucks would receive more or less equal damage.

Lets have the truck accelerating and have a constant acceleration even on impact and after impact. Also, the impacted truck is now accelerating along with the impacting truck at the same acceleration, into another truck with the same weight and mass. What will happen then?

15 floors can not cause 95 floors to collapse, crush, whatever term you like.

They sure can, when 15 floors crush one floor, then 16 crush one floor, then 17 floors crush one floor, then 18 crush one floor. Boy pretty soon you have 99 floors crushing one floor. WOW!

Oh by the way, did you recognize the error with your physics yet? I'll give you a hint: you are doing horizontal collisions. The WTC collapse had objects falling. Mr. Physics, figure it out.

Originally posted by GenRadek

Originally posted by ANOK
15 floors can not cause 95 floors to collapse, crush, whatever term you like.

They sure can, when 15 floors crush one floor, then 16 crush one floor, then 17 floors crush one floor, then 18 crush one floor. Boy pretty soon you have 99 floors crushing one floor. WOW!

Oh by the way, did you recognize the error with your physics yet? I'll give you a hint: you are doing horizontal collisions. The WTC collapse had objects falling. Mr. Physics, figure it out.

That is the total PHYSICS Bullsh# people insist on believing.

15 LEVELS would crush the 16th and 15th LEVELS simultaneously. The 16th would accelerate from zero to some degree and slow down 15, 14, 13,...3, 2 & 1 to some degree.

AND THE ENERGY REQUIRED TO CRUSH THOSE TWO LEVELS would slow down the entire mass also.

Then LEVELS 17 and 14 would crush each other and the process would repeat. The starting 15 LEVELS would run out long before the 90. The people who insist on believing the collapse nonsense have to come up with ridiculous rationalizations.

That magical acceleration of more and more mass while being destroyed is energetically IMPOSSIBLE.

www.youtube.com...

As my model demonstrates. Mass must be accelerated and supports destroyed, which requires energy and the only source of energy SUPPOSEDLY is the kinetic energy of the mass falling from the top. Any other energy sources would mean that the Official Conspiracy Theory is crap.

psik

Originally posted by psikeyhackr


That is the total PHYSICS Bullsh# people insist on believing.

15 LEVELS would crush the 16th and 15th LEVELS simultaneously. The 16th would accelerate from zero to some degree and slow down 15, 14, 13,...3, 2 & 1 to some degree.

Say WHAT?

You pulled this nonsense out of your backside and say what I posted is BS?



I cannot even begin to follow your backward thinking. Are you forgetting gravity?

AND THE ENERGY REQUIRED TO CRUSH THOSE TWO LEVELS would slow down the entire mass also.

Then LEVELS 17 and 14 would crush each other and the process would repeat. The starting 15 LEVELS would run out long before the 90. The people who insist on believing the collapse nonsense have to come up with ridiculous rationalizations.

That magical acceleration of more and more mass while being destroyed is energetically IMPOSSIBLE.

So in other words, the mass of the floors that are being destroyed by the falling mass is disappearing? Is this what you are saying?

As my model demonstrates. Mass must be accelerated and supports destroyed, which requires energy and the only source of energy SUPPOSEDLY is the kinetic energy of the mass falling from the top. Any other energy sources would mean that the Official Conspiracy Theory is crap.

psik

Your model is not a representation of the WTC design. not by a long shot. Therefore, do not bring this up again as it does not apply. Mass is being accelerated, by the number one thing we learn in physics: GRAVITY!!!!!!!!!! The only supports holding up floors? SEAT TRUSSES!

reply to post by GenRadek


No, I and others have already shown your claims do not make sense.

BOTH impacting floors would be damaged, that is what has been shown, not that 15 floors cannot crush 95. Even though they can't of course, which is what you are ultimately claiming, however you put it.

15 floors crushing one floor is wrong, because the impacted floor, floor 95, has the same structure holding it up as the impacting floor, 96th floor, has between it and the other 14 floors above it. There is still less pushing down as there is pushing up, or back, against the falling mass. If the connections failed at the impacted floor, 95, then the connections would also fail on the impacting floor, 96, both floors would lose Ke instantly, and the rest of the dropping floors would drop on the first impacting floor, 96, crushing both floors, 95 & 96. Thus you would be losing mass, and Ke, needed to continue the collapse. Complete collapse is impossible, period. Scream for proof all day if you wish, physics is the proof.

This simple test proves it...

www.fearofphysics.com...

Try it for yourself, don't be afraid, share you results. Put your brains where your mouth is.

Originally posted by ANOK
reply to post by GenRadek

 

No, I and others have already shown your claims do not make sense.

BOTH impacting floors would be damaged, that is what has been shown, not that 15 floors cannot crush 95. Even though they can't of course, which is what you are ultimately claiming, however you put it.

15 floors crushing one floor is wrong, because the impacted floor, floor 95, has the same structure holding it up as the impacting floor, 96th floor, has between it and the other 14 floors above it. There is still less pushing down as there is pushing up, or back, against the falling mass. If the connections failed at the impacted floor, 95, then the connections would also fail on the impacting floor, 96, both floors would lose Ke instantly, and the rest of the dropping floors would drop on the first impacting floor, 96, crushing both floors, 95 & 96. Thus you would be losing mass, and Ke, needed to continue the collapse. Complete collapse is impossible, period. Scream for proof all day if you wish, physics is the proof.

This simple test proves it...

www.fearofphysics.com...

Try it for yourself, don't be afraid, share you results. Put your brains where your mouth is.

Oh ANOK, ANOK, ANOK...............

Pity, really. Are you forgetting in what orientation the collisions are occurring? Are the floors collapsing horizontally? What extra forces are in play? (I'll give you a hint: Think of Newton and the apple tree)
There is your error right there. My brains are just where they should be, in my skull. Where are yours?

How exactly can the floors of the collapsing block be destroyed in the same manner as the floors being impacted below? I really want to hear how this is physically possible.

Also, ANOK, I am still waiting, into the third month, of when you are going to provide evidence of any sort of floors being ejected horizontally in order to prove your assumption that the majority of mass was magically ejected outside the footprint and thats why the collapse should have stopped.

Originally posted by ANOK
reply to post by GenRadek

 

Complete collapse is impossible, period. Scream for proof all day if you wish, physics is the proof.

This simple test proves it...

Well clearly it's not impossible ANOK, so why keep asserting yourself in that manner. They collapsed. Completely. And, yes, whether you like it or not, they did so without the aid of any explosives of any kind.

You want to know why? Because there is no real evidence of explosives. At all. And you know this.

But forget that- Why not instead just debate the evidence (or lack there of) for the use of explosives or the magical thermite? (Which btw, is a dead theory.)

Lets talk about the logistics of rigging up a whole tower (2x, and without any one seeing- oh and WTC7 too!) to come down the way it did. Let's talk about where the explosives and therm?te had to be planted in order to achieve the collapse that you're so intent on believing was impossible to initiate and continue on it's own. How much of the stuff was used? Why didn't we notice any of these incendiary devices going off prior to collapse?

Care to offer up any theories on this? And perhaps with some supporting evidence?

Originally posted by ANOK
So no takers huh?

No one jumping all over this post huh?

Afraid of the physics huh?

www.fearofphysics.com...

Here are two objects of the same mass hitting each other at the same velocity...

The redtruck came into the collision at 40.23 meters per second (90.00 miles per hour)
It left moving at -40.23 meters per second (-90.00 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

The redtruck came into the collision at -40.23 meters per second (-90.00 miles per hour)
It left moving at 40.23 meters per second (90.00 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

Both objects reacted equally in the collision, equal mass, equal result. Consider momentum conservation, and both trucks would receive more or less equal damage.

15 floors can not cause 95 floors to collapse, crush, whatever term you like.

Maybe it's just that your comparisons with trucks and slamming concrete slabs together are so silly it's not worth anybody's time? The buildings were not solid objects and the upper section didn't fall as a solid object as evidenced by the scattering of the framework and the remaining sections of core and outer skin columns that were still standing for a few seconds after the initial collapse. Every time I ask you to explain how that fits in your theory you run like a scared wittle wabbit. Your silence on this is deafening and highlights your shortcomings.

Originally posted by ANOK
So no takers huh?

No one jumping all over this post huh?

Afraid of the physics huh?

www.fearofphysics.com...

Here are two objects of the same mass hitting each other at the same velocity...

The redtruck came into the collision at 40.23 meters per second (90.00 miles per hour)
It left moving at -40.23 meters per second (-90.00 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

The redtruck came into the collision at -40.23 meters per second (-90.00 miles per hour)
It left moving at 40.23 meters per second (90.00 miles per hour)
It was jolted so much by the collision that it was sent back in the opposite direction!

Both objects reacted equally in the collision, equal mass, equal result. Consider momentum conservation, and both trucks would receive more or less equal damage.

15 floors can not cause 95 floors to collapse, crush, whatever term you like.

Anok this clearly shows an awful lot of structure remaining after the initial collapse and I would say it's a substantial portion all the way up to the impact zone. Notice how much of the core and skin are still standing. It is absolute proof that your 15 vs 95 theory is nonsense no physics necessary.

youtu.be...