Why a one-way Crush down is not possible

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Gamolon said:
Please answer the question I asked before. If I were to pound a perimeter column into the ground and then welded an "L" shaped connection to said column and then hit it with a sledgehammer, where is the most stress going to occur?
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Pls provide a sketch of your design + sledge hammer and location of impact/energy applied.
 
Gamolon said:
What if I used some thread to tie the weights to the outside dowels by cutting a tiny notch in the outside of the perimeter dowels and looping the
thread into that notch. Then drill a hole through the edge of the weight and looped the thread through there and tied it.

Do you think the collapsing weights could pull some of the dowels down with themsleves if the thread somehow held in a couple of spots?
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Maybe the trick here would be more but smaller diameter dowels. Dowels braced at every floor, but which would snap if several floors became unbraced. The WTC columns could not have stood for their full height without the floors, even with NO loading on them. They would have snapped under their own weight as soon as there was any perturbation to their vertical position.
 
R.Mackey said:
Heiwa, and apparently the others participating in this Romper Room version of uneducated speculation, simply do not understand scaling. That's all there is to it.
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??? A one-way Crush down of a structure A by a piece C of it being dropped on A is not possible in any scale. Anyway - all my educated descriptions are full scale. Scale has nothing to do with the matter. It is simply an excuse by uneducated people that nobody can produce a structure that you can one-way crush down.
 
sylvan8798 said:
You need a sketch? You're really unable to conceive such a simple contraption from his description alone?
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OK - the highest stress will occur at contact point sledge hammer/L shaped connection assuming it is a small area. But as the contact point is pretty strong it will just be deformed. Other highly stressed area is the sledge hammer handle! Maybe it will break?
Deformation of the L shaped connection, or breaking it, may also produce the funny effect that the sledge hammer slips off and continues displacing somewhere else? Hitting the person holding the handle?

You know, releasing and applying energy on a structure to produce a force that should, e.g. damage the structure, is not so easy. If something breaks or deforms, the force may slip off and the energy is applied somewhere else. Happens in every scale.
 
Gamolon said:
Please answer the question I asked before. If I were to pound a perimeter column into the ground and then welded an "L" shaped connection to said column and then hit it with a sledgehammer, where is the most stress going to occur?
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"it will bounce but both sections will survive [part a divided by part b squared minus part c = turtles]"
lol
 
bill smith said:
Seen his yet Heiwa ?
http://www.911blogger.com/node/20533
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This says it all.

How is a non-specialist like me to evaluate the reasonableness of Bazant's upper bound? One obvious way is to compare it with the estimates of other experts. I am aware of two of these, one due to Gregory Szuladzinski in Journal of Engineering Mechanics and the other from Tony Szamboti in "The Missing Jolt", Journal of 9/11 Studies.
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The guy is an idiot.
 
Gamolon said:
How about this model.

Let's take a 25lb weight used for weight lifting. The round weights with a hole in the middle that can be slipped onto a weight lifting bar. Lets get 6, 1" diameter wooden dowels and pound them into the ground around the perimeter of the weight mentioned above. Let's take a single 1" diameter wooden dowel and pound it into the ground in the center of the ring we just created.

Now let's slip one of the 25lb weights mentioned onto the center wooden dowel down to about an inch from the ground. We'll put one thumbtack (the kind with the plastic head on them, not the flat heads) in each of the perimeter wooden dowels right below the weight and put two thumbtacks, opposite one another on the center wooden dowel.

We'll build our tower up 40 feet high with a "floor" weight every foot.

We'll then created a seperate section the same way, but only 1/10th the size, which would be 4 weights (or 100lbs). We will then position the 1/10th section above the 40 foot tower we created using a dowel to center it above.

We then drop the 1/10th section down the centering dowel from a height of 10 feet above.

What do you think would happen? Are the "thumbtack" connections going to arrest the upper part and stop it from bringing everything down the the ground?
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Nice one Gamalon....

I solved the stupid Heiwa Challenge too, with Pizza boxes.! Mine fell down too

I thought I was first but found that every 100 posts or so there is a solution posted. I have seen 6 schemes so far.
 
Heiwa said:
??? A one-way Crush down of a structure A by a piece C of it being dropped on A is not possible in any scale. Anyway - all my educated descriptions are full scale. Scale has nothing to do with the matter. It is simply an excuse by uneducated people that nobody can produce a structure that you can one-way crush down.
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Thirteen collapsing floors crush the floor below. Then fourteen collapsing floors crush the floor below. Then fifteen, then sixteen...

You can run, but you can't hide.
 
FineWine said:
And nothing Mackey, Newton's Bit, tfk, or any real engineer tries to explain about the problems associated with scaling will ever make the slightest impression on you? When thousands of tons of falling debris hit the floor immediately below, it ain't soft cardboard pizza boxes or spaghetti falling on spaghetti.
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I was thinking about this this morning. In order to properly scale a skyscraper analogue with spagetti, you would have to make each floor weigh fairly close to the limit of what the spaghetti can bear without breaking.

Why? Because that is how skyscrapers are built. It would be wasteful to put in enough steel to make it many times stronger than it needs to be in order to withstand normal loads.

When part of the building starts moving independent of the rest of it, that is not a normal load. Engineers make a cost-benefit analysis and bank on the prediction that this won't happen.

(Again, I'm sure most of you know this...including our resident truthers...but writing it all down helps me understand it better myself.)
 
Heiwa said:
OK - the highest stress will occur at contact point sledge hammer/L shaped connection assuming it is a small area. But as the contact point is pretty strong it will just be deformed. Other highly stressed area is the sledge hammer handle! Maybe it will break?
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You don't know?

Where did you study engineering, again?

I'm not an engineer either, but I do know that in order to determine what will give way in this scenario you must know the relative strengths and flexibility of the sledge hammer handle, the L-shaped connector, it's connection to the spandrel, and of course the spandrel itself.

The weakest point will tend to break, unless it is flexible/plastic enough to absorb the energy by bending. (I'm sure there are other things to take into consideration as well, such as the angle of the blow, but that would needlessly complicate the model, I think.)

Deformation of the L shaped connection, or breaking it, may also produce the funny effect that the sledge hammer slips off and continues displacing somewhere else? Hitting the person holding the handle?
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What are you asking, and who are you asking it to?

Add another potential failure point: The connection of the sledge hammer head to the handle. If this is the weakest point, then it will probably fail here. Why is this a "funny effect"?

You know, releasing and applying energy on a structure to produce a force that should, e.g. damage the structure, is not so easy.
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Um...English?

If something breaks or deforms, the force may slip off and the energy is applied somewhere else. Happens in every scale.
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I'm betting you're an accountant rather than an engineer, because you have supplied us here with information that is completely accurate and yet totally useless.
 
Here's another one, to test Bill's (or Heiwa's) knowledge of gravity and resistance:

A 200-lb man and a 50-ton King Kong make a suicide pact and jump off the Empire State Building.

Which of the following will happen?

A. They hit the ground at the same time
B. King Kong hits first
C. The man hits first
 
aggle-rithm said:
Here's another one, to test Bill's (or Heiwa's) knowledge of gravity and resistance:

A 200-lb man and a 50-ton King Kong make a suicide pact and jump off the Empire State Building.

Which of the following will happen?

A. They hit the ground at the same time
B. King Kong hits first
C. The man hits first
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Kong might eat the man on the way down. Does that fall under A?
 
aggle-rithm said:
Hmmm...

If he then gets motion sickness and barfs, then it would depend on which direction he is facing when the vomitus emerges.
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So, if the big ape is facing down when he tosses his cookies, the man will be moving at greater than free fall velocity, which PROVES inside jobby-job.

Physics is fun when you're nuts.
 
Heiwa, can you please address the contradiction you have made with your following quotes:

Heiwa said:
Is it? I clearly say that the intact floors are just hanging on the columns; like pictures on a wall.
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Heiwa's website said:
Section C consists of 14 horizontal elements/floors, each with mass m as section A, stacked on top of each other with vertical support elements in between of height h. Total mass of C is 14 m. It is 52 meters tall.
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Which is correct?
 
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