Heiwa's bathroom scale experiment

[Heiwa]

AA. Let's see your calculations as to exactly how much energy is dissapated (energy actually never gets 'consumed') by fracturing of both the upper and lower structure. Then tell us what the effect of the mass of the rubble on the lower structure floor spans will be. A ton of gravel will have the same load due to gravity as will a ton of solid(rigid) steel.

BB. Still an AK-47 for example, can fire a bullet right through a concrete block and keep going with enough velocity enough to seriously injure or kill a person on the other side of that block.


CC. They take for granted that a building undergoing a collapse will see that collapse arrest??!! That's a hell of a claim there H. Care to back that up with any quotes from experienced fire fighters or similar? You know, anyone who would be in the habit of making sure there is a safety perimeter around a building in danger of collapse.



DD. In your opinion is one thing. You have made claims that require that you show Bazant's approximations to be grossly in error as to the conclusions arrived at. You have done no more than say it is so with absolutly none of the requisite work needed.

AA. Good that you agree that local failures may occur at contact between two non-rigid objects. To calculate the energy required to produce a local failure is fairly easy. Elastic deformation is just force times deformation. Plastic deformation is a little more elaborate; you have to calculate the energy to produce the plastic hinge in the part under consideration. Not too difficult. And finally you must calculate the energy required to produce the fracture that develops in the plastic hinge. It is also straigthforward.

Sometimes the local failure suddenly stops at the end of the fracture in the part = arrest. Or the fracture cuts the part in two pieces ... and then more local failures occur due to the force is now applied to other parts. They will be treated in the same manner.

BB. You cannot compare the WTC1 upper block dropping down at low velocity on the lower structure with a AK 47 depleted uranium bullet hitting something.

CC. See AA. Yes local failures are always arrested ... at the tip of the many fractures you always find in the structures when destruction is arrested. Fire fighters know this. Always good to make a safety perimeter. Then you can scrutinize the fractures. Checking backwards you find where the failure started and can conclude what initiated it, gravity ... or something else. Pity FBI did not study any fractures in the WTC rubble. Many of them were not caused by gravity, in my opinion.

DD. I think I have clearly shown that the Bazant's assumptions are those of a con man. But thank you for your input. It assists to improve my claims.

 

[jaydeehess]

AA. Good that you agree that local failures may occur at contact between two non-rigid objects. To calculate the energy required to produce a local failure is fairly easy. Elastic deformation is just force times deformation. Plastic deformation is a little more elaborate; you have to calculate the energy to produce the plastic hinge in the part under consideration. Not too difficult. And finally you must calculate the energy required to produce the fracture that develops in the plastic hinge. It is also straigthforward.

I do not have to calculate anything, you have to calculate these energies in order to back your claims. I bolded a significant part of your above post. If it is not too difficult then why are you argueing that it is unneccessary instead of doing it? It would remove this discussion from a "yes it is - no it isn't" level to a more objective plane.
Until you do so you are just hand waving and asking us to believe you.
I do not buy used cars on that type of information, why should I buy your arguement?

Sometimes the local failure suddenly stops at the end of the fracture in the part = arrest. Or the fracture cuts the part in two pieces ... and then more local failures occur due to the force is now applied to other parts. They will be treated in the same manner.

More hand waving...........

BB. You cannot compare the WTC1 upper block dropping down at low velocity on the lower structure with a AK 47 depleted uranium bullet hitting something.

Wo said anything about depleted uranium ammo in a rifle?

CC. See AA. Yes local failures are always arrested ... at the tip of the many fractures you always find in the structures when destruction is arrested. Fire fighters know this. Always good to make a safety perimeter. Then you can scrutinize the fractures. Checking backwards you find where the failure started and can conclude what initiated it, gravity ... or something else. Pity FBI did not study any fractures in the WTC rubble. Many of them were not caused by gravity, in my opinion.

More hand waving...... I asked you for a quote from any organization that would have responsibilty and experience around buildings in danger of collapse. Instead you supply more of your own personal opinion.

DD. I think I have clearly shown that the Bazant's assumptions are those of a con man. But thank you for your input. It assists to improve my claims.

You 'think' wrong, you haven't.
If my input actually ever gets you to attempt to calculate the energies involved to a better approximation than Bazant used I will be satisfied but I am not going to hold my breath waiting for it.

 

[peteweaver]

Tell you what Heiwa, place the scales outside do a jump off your door step, onto the scales, then do a swan dive off your roof onto them see if the difference in kinetic energy alters your mass, and force of impact...

Dare you ?

Or do you realise that kinetic energy adds to your load, and the force of impact would therefore be greater ?

 

[Heiwa]

I do not have to calculate anything, you have to calculate these energies in order to back your claims.

It's a pity Bazant does not do any serious calcuations about local failures. He assumes that the rigid upper block impacts - as one rigid unity - on the lower structure ... that behaves like a spring (!?) with spring constant C = 90 GN/m. Assumed by Bazant, the con man!

Hm, that's a very stiff spring. It does not deform at all - unless you put 90 GN on it ... and it deforms 1 m! Springs are normally more flexible. I would estimate that C = 1 GN/m or less ... if WTC1 was a spring, which I doubt.

It is easy to check what C of the lower structure actually is. Make a beam model of the lower structure and compress it. If you need a force 90 GN to deform it 1 m, C = 90 GN/m. If you only need a force 1 GN, C = 1 GN/m.

If you assume that the lower structure is a solid steel rod 10 m² that only compresses vertically with no transverse deflections, then C = 90 GN/m. If you model that the lower structure consist of 280+ springy, flexible columns that can deflect sideways (between floors) you will get C = 1 GN/m. Such spring will just deform like a bed with children jumping on it. The children bounce. No collapse.

Anyway - so a 'spring' with C = 90 GN/m is pretty stiff ... rigid. Like a steel floor. Anything hitting such a spring ... like an upper block ... would get destroyed at once ... unless it was rigid.

The local pressures between a lower structure spring with C = 90 GN/m and a rigid upper block would really be enormous. OK - the upper block cannot get damaged ... it is rigid ... and the lower structure does not really deform - C = 90 GN/m, what happens? No local deformations anywhere. No, a shock wave is produced!

It goes through the spring at very high speed ... disappears in the ground. No seismic recordings of that, though.

And then ... suddenly, the very stiff spring (read lower structure) starts to 'globally collapse' from top to bottom. Bazant has a very strange explanation for that. Floors getting loose, etc.

Actually ... all destruction is always sideways (!) at regular intervals - as no upper block is seen any longer.

Just look at the videos. Sections of lower structure implodes one after the other from top down. The implosions are associated with a fountain of debris and dust sent sideways ... all the time below and above the imploded sections. Also air jets occur ... well below the real destruction of sections. The air jets are a result of what sets off the implosions.

Quite impressive. Many people think it is a global collapse caused by something dropping down ... but they are fooled. Nothing is dropping down. The upper block was the first to implode.

I really wonder what energies were required to produce all that destruction, debris, dust and smoke. Gravity? No chance. Gravity is not strong enough.

Just jump yourself. Or just drop. Gravity, you know. You or gravity do not globally collapse anything.

 

[dtugg]

Come on guys, Heiwa is the smartest person in the world, give him some credit. He is right and the entire engineering community is wrong. Or something like that.

 

[Lennart Hyland]

Nists paper and Bazants paper on the collapse of the towers are two different scenarios, or am I wrong?

And can someone ask Heiwa exactly were Bazant makes the assumption that the upper block is rigid?

 

[jaydeehess]

It's a pity Bazant does not do any serious calcuations about local failures.

Its a pity that you do no calculations whatsoever.

He assumes that the rigid upper block impacts - as one rigid unity - on the lower structure ... that behaves like a spring (!?) with spring constant C = 90 GN/m. Assumed by Bazant, the con man!

Hm, that's a very stiff spring. It does not deform at all - unless you put 90 GN on it ... and it deforms 1 m! Springs are normally more flexible. I would estimate that C = 1 GN/m or less ... if WTC1 was a spring, which I doubt.
...
<<snip>>.....I really wonder what energies were required to produce all that destruction, debris, dust and smoke. Gravity? No chance. Gravity is not strong enough.

You think you got closer to doing any math by including a number?

Just jump yourself. Or just drop. Gravity, you know. You or gravity do not globally collapse anything.

Quite the contrary. I can indeed fashion a structure that will support me with no problem which if I jump on it, it collapses.
In fact I have done this many times, I can stand on an empty pop can without it collapsing but if I merely stomp down on it, not even using all my weight, it crushes down.


The more you post the more I have to suspect that you are not an engineer. You obviously cannot comprehend what Bazant is doing or the concepts involved.
If you really are an accredited engineer then it looks like you are following in the footsteps of the designers of the Vasa.

 

[Heiwa]

I can indeed fashion a structure that will support me with no problem which if I jump on it, it collapses.
In fact I have done this many times, I can stand on an empty pop can without it collapsing but if I merely stomp down on it, not even using all my weight, it crushes down.


The more you post the more I have to suspect that you are not an engineer. You obviously cannot comprehend what Bazant is doing or the concepts involved.
If you really are an accredited engineer then it looks like you are following in the footsteps of the designers of the Vasa.

Your pop can example is quite good. Now put 10 cans on top of one another taped together and jump on them. The cans now act as spring and dampen your impact. Note that the cans bulge out between tops/bottoms = elastic deformation. Absorbs plenty of energy.

Don't worry about my engineering credentials. They are very good.

Quite clear that Bazant is spreading misleading info.

 

[Heiwa]

This is not supposed to happen during the Heiwa bathroom scale experiment.

http://uk.youtube.com/watch?v=dtx_GcFCs6c&feature=related

 

[jaydeehess]

Your pop can example is quite good. Now put 10 cans on top of one another taped together and jump on them. The cans now act as spring and dampen your impact. Note that the cans bulge out between tops/bottoms = elastic deformation. Absorbs plenty of energy.

Don't worry about my engineering credentials. They are very good.

Quite clear that Bazant is spreading misleading info.

,,,,,,,,,,,, and still none of those "fairly easy" and "not too difficult" calculations.

Actually, if I tape, or even solder, those 10 cans in line together and if I merely stand on the top of that column it will bend over and buckle. With no lateral support it will fail to hold my weight.

Take it up with Euler if you do not believe me.

 

[Heiwa]

Actually, if I tape, or even solder, those 10 cans in line together and if I merely stand on the top of that column it will bend over and buckle. With no lateral support it will fail to hold my weight.

Take it up with Euler if you do not believe me.

I know Euler. In the 10 cans experiment only one can will fail at overload - after that the loose load is no longer applied to the remaining 9 cans. Try again.

 

[240-185]

This is not supposed to happen during the Heiwa bathroom scale experiment.

Stop speaking of yourself at the third person.

 

[jaydeehess]

I know Euler. In the 10 cans experiment only one can will fail at overload - after that the loose load is no longer applied to the remaining 9 cans. Try again.

You have created a different situation. The 10 can column cannot support a simple load of 90 Kg without buckling. It will buckle in an arc and likely fail by creasing near the center if the bottom can is fixed to the ground.
However if you used three of these columns and laterally connected them I could stand with my entire weight on any single column with no problem because the lateral support would resist the buckling and the column itself can support a lot more compressive load.


This is more akin to how the core columns failed after the floor spans were violently removed leaving the columns wioth no lateral support.

As I have stated several times now, the mass of the top portion of the towers came down and would have impacted the floor of the next level down. The mass of that upper portion had been designed to be taken by the columns but that mass is no longer on the columns, it is on the floor pan. The floor pan was never designed to transfer that amount of load to the columns let alone the impact forces that would have resulted. The floor pan/truses fail in milliseconds under this load thus removing lateral support betweeen perimeter and core columns. The mass continues down relatively unchanged and moving faster when it impacts the next floor immediatly failing that floor. Now the columns of the lower structure have two levels of no lateral support.

Alone these columns could probably stand perhaps 4-5 stories with only a slight bend but they are not sitting there in pristine, and quiet, condition. There are hundreds of tons of material buffeting them. They buckle and snap.

Indeed although the trusses and floor pans were crushed, the columns were bent or snapped in relatively long sections. The perimeter columns that were spaced closely together and connected to each other along the plane of the outer wall, did survive in some quite large sections as well.

This is essentially what Bazant says. He supplies his calculations to support his model.

You also have a model but you supply no mathematical backing for it and we are left to take your say-so. That puts you at the same level of a used car salesman.

I will continue to read this thread but will no longer post until you have supplied some mathematical bassis for your claims.

 

[Heiwa]

You have created a different situation. The 10 can column cannot support a simple load of 90 Kg without buckling. It will buckle in an arc and likely fail by creasing near the center if the bottom can is fixed to the ground.
However if you used three of these columns and laterally connected them I could stand with my entire weight on any single column with no problem because the lateral support would resist the buckling and the column itself can support a lot more compressive load.


This is more akin to how the core columns failed after the floor spans were violently removed leaving the columns wioth no lateral support.

As I have stated several times now, the mass of the top portion of the towers came down and would have impacted the floor of the next level down. The mass of that upper portion had been designed to be taken by the columns but that mass is no longer on the columns, it is on the floor pan. The floor pan was never designed to transfer that amount of load to the columns let alone the impact forces that would have resulted. The floor pan/truses fail in milliseconds under this load thus removing lateral support betweeen perimeter and core columns. The mass continues down relatively unchanged and moving faster when it impacts the next floor immediatly failing that floor. Now the columns of the lower structure have two levels of no lateral support.

Alone these columns could probably stand perhaps 4-5 stories with only a slight bend but they are not sitting there in pristine, and quiet, condition. There are hundreds of tons of material buffeting them. They buckle and snap.

Indeed although the trusses and floor pans were crushed, the columns were bent or snapped in relatively long sections. The perimeter columns that were spaced closely together and connected to each other along the plane of the outer wall, did survive in some quite large sections as well.

This is essentially what Bazant says. He supplies his calculations to support his model.

You also have a model but you supply no mathematical backing for it and we are left to take your say-so. That puts you at the same level of a used car salesman.

I will continue to read this thread but will no longer post until you have supplied some mathematical bassis for your claims.

Nice try, jaydeehess, but all nonsense.

Bazant does not provide any calculations: his mass is 75% bigger than actual and his spring constant C of the tower is 140 times (14 000%) bigger than the actual one (if you can talk about a spring constant of a tower?).

Using such stupid assumption, plus that the dropping mass is indestructible, he suggests that this mass crushes down 95 floors one after the other by gravity only.

Look at the videos, FGS. There is no dropping mass to be seen anywhere.

And a dropping mass due to gravity does not eject big chunks of walls in all directions and pulverize the floors to dust. It seems 10 000 times more energy is at work during the destruction than caused by a little low weight, flexible upper part assembled by some columns and a few floors + plenty of air. The upper part should have stopped at once up top after 'impact'.

Jumping on a bathroom scale does not destroy the whole house where the scale is located.

 

[Grizzly Bear]

Nice try, jaydeehess, but all nonsense.

Please restudy everything you've been taught about column failure modes and slenderness ratios. Jaydeehess has demonstrated the non-technical basics of the concept. You on the otherhand demostrate no such familiarity despite knowing the fancy terminolgy.

Bazant does not provide any calculations: his mass is 75% bigger than actual and his spring constant C of the tower is 140 times (14 000%) bigger than the actual one (if you can talk about a spring constant of a tower?).

This is a strange criticism coming from you, who declines to provide the math to substantiate your own claims. Hypocrite much?

Look at the videos, FGS. There is no dropping mass to be seen anywhere.

Your logic is that if you cannot see a mass there, then it does not exist. Invalid and irrelevant argument, try again

And a dropping mass due to gravity does not eject big chunks of walls in all directions and pulverize the floors to dust.

Heresay, is not a valid argument, particularly when you offer no substantiation for your reasoning.

It seems 10 000 times more energy is at work during the destruction than caused by a little low weight, flexible upper part assembled by some columns and a few floors + plenty of air. The upper part should have stopped at once up top after 'impact'.

Reductive fallacy

Underestimating the scale of the section above the impact region?
Oversimplifying... Heiwa.... if you're going to use misleading arguments, please try harder...

Jumping on a bathroom scale does not destroy the whole house where the scale is located.

The analogy fails no matter how many goals posts you shift. We're talking about the structural failure within a building using a footprint the size of a soccer field, and the height of a conventional high rise structure in smaller cities. Nothing about the real thing is "small".

 

[Heiwa]

Please restudy everything you've been taught about column failure modes and slenderness ratios. Jaydeehess has demonstrated the non-technical basics of the concept. You on the otherhand demostrate no such familiarity despite knowing the fancy terminolgy.



This is a strange criticism coming from you, who declines to provide the math to substantiate your own claims. Hypocrite much?


Your logic is that if you cannot see a mass there, then it does not exist. Invalid and irrelevant argument, try again



Heresay, is not a valid argument, particularly when you offer no substantiation for your reasoning.


Reductive fallacy

Underestimating the scale of the section above the impact region?
Oversimplifying... Heiwa.... if you're going to use misleading arguments, please try harder...



The analogy fails no matter how many goals posts you shift. We're talking about the structural failure within a building using a footprint the size of a soccer field, and the height of a conventional high rise structure in smaller cities. Nothing about the real thing is "small".

It seems you haven't read my articles at http://heiwaco.tripod.com/nist.htm and http://heiwaco.tripod.com/nist3.htm? All the math to substantiate my claims are there.

The bathroom scale experiment is just demonstrate the same thing more visually ... at no risk.

 

[240-185]

The bathroom scale experiment is just demonstrate the same thing more visually ... at no risk.

What about THIS???

 

[MIKILLINI]

The bathroom scale experiment is just demonstrate the same thing more visually ... at no risk.

The bathroom scale demonstrates nothing for your arguments. According to you it does, but nobody else is convinced or even swayed by this silly comparison.
You seem unwilling to provide mathematical calculations to back up your arguments, therefore you fail in your endeavor here because you have no key ingredient of calculations.

 

[Heiwa]

The bathroom scale demonstrates nothing for your arguments. According to you it does, but nobody else is convinced or even swayed by this silly comparison.
You seem unwilling to provide mathematical calculations to back up your arguments, therefore you fail in your endeavor here because you have no key ingredient of calculations.

Pls, see post #276.

An interesting article how a vertical column behaves in compression is at http://www.ochshorndesign.com/writings/buckling/index.html , i.e. it deflects elastically sideways between supports before collapse.

If many columns are connected in a tower and supported by horizontal beams this behaviour comes into play. The multi columns tower will deform vertically much more than just due to pure axial compression of the column, i.e. the multi columns tower is more flexible than if all columns are assumed bundled together as a solid rod that can only compress axially.

It is therefore I assume in my papers (based on some simple modelling) that the WTC1 tower has a spring constant C = 0.5 GN/m (due to 280 columns (variable cross areas) over 4000 m² supported by 90 floors) and is compressed 1.56 m due to a force F of 0.78 GN and energy input 0.61 GJ (upper part dropping down). Most of that compression is due to the columns bulging out between supports. Such force will not overload the lower structure. The top part should have bounced and stopped up top if it ever dropped. Just like jumping on a bathroom scale.

Bazant assumes that C = 70 GN/m (all columns bundled together to a 6 m² rod) and that the tower only compresses axially 0.14 m due to same energy input (no bulging), while the force becomes 9.24 GN, which Bazant says is overload that causes global collapse, i.e. the upper part, rigid, indestructible, punches through everything below. Nice try by a con man! Has nothing to do with reality.

 

[TheDaver]

Pls, see post #276.

Epitome of trutherdom. You can’t even be honest about the content of your own webpages.

(Still waiting for a reply to my earlier post, by the way.)