Heiwa, do you understand why nobody takes you seriously? I am not even sure if you are being serious when you post here. For your sake, I hope you are an elaborate troll. The implications otherwise aren't very good.
But I am happy to have found a new Heiwa type experiment that should convince my fellow engineers what happens when you drop a structure on a similar, but bigger piece, of structure. Try to destroy a sponge by dropping another sponge on it. Actually WTC1 upper part has all the charcteristics of a sponge (consisting of strong elastic columns, weak elastic floors and plenty of holes (air)), i.e. not very rigid and definitely not homogeneous.
But as already pointed out the upper part will slide off the spring as the columns will never meet at contact/impact and the upper part is not rigid - it compresses also. This is under the assumption that the upper part actually drops almost free fall and remains intact until and after 'impact'. Under this assumption, the upper part misses, I suggest that multiple local failures occur ... and that's it. No global collapse. Just floors getting entangled.
Making the unit distance one meter I get the unit force 0.5 GJ applied to every column in proportion to its cross area/total cross area. Just to get a feeling that the lower structure behaves like a sponge, i.e. it deforms in 3-D. Anybody doing structural analysis of WTC1 can verify how flexible WTC1 was.
But my sponge has not uniform properties everywhere. It is evidently less holes in it at the bottom, etc. No way another little sponge dropping from the sky can globally collapse my sponge, though.
I just read this whole thread. MY BRAIN BURNS!!!!!!!!!
Hm, The total energy 1.12 GJ (or so - 1.22 GJ ?) is required to compress the spring 1.56 m. 0.61 GJ is applied from outside, 0.51 GJ (or so - 0.61GJ ?) is added during compression as the force applied is moving that distance (actually when the upper part is decelerating). After that any motion of the upper part is zero. Then the bounce starts! Just like children jumping in a bed.
Thanks for considering my WTC1 spring constant C = 0.5 GJ/m reasonable.
Which of course brings up the question, as shown by the photos, of:
How can this:
(insert image of floors)

Stop this:
(insert image of the falling upper block)

Pls read my article.
Thanks for repeating the question, but Heiwa is not going to answer the question directly, because he knows that he can't explain it without contradicting his own claims. Heiwa cannot explain how the floor should stop the falling upper block.
Heiwa:
When are you going to admit that your webpage (or whatever it is) with all your fantasies on it is far more important to you than facts?
I see a ships' welder with delusions of grandeur.
He does not acknowledge gravity, why worry about your question. Soon he will be on ignore; like gravity is to him.
http://www.internationalskeptics.com/forums/vbimghost.php?do=displayimg&imgid=9463
... Heiwa is not going to answer the question ...
Heiwa,Sorry, steel structures do not collapse due to gravity and local failures - too much redundancy built into them.
Heiwa,
You've got a massive case of "circular illogic" working here.
You have attempted to use a definition to prove your conclusion.
BY DEFINITION, non-progressive failures do not progress from a single point to global failure.
BY DEFINITION, progressive failures do.
Are you truly saying that "progressive failures are unknown in large steel structures"?
Surely you are not that unknowledgeable about the world of large structures?
Surely someone has pointed out to you buildings such as the Sight & Sound Theater, McCormick Plaza, and the Windsor Towers. Surely you have heard about the massive building failures that happened as a result of the fire bombings of the cities of Dresden & Tokyo. Surely you have seen flaming oil derricks collapse.
All examples of progressive failure of large steel structures due to fire alone.
To be sure, these types of failures are extremely rare. It is a testament to the dedication of engineers who are acutely aware of single point failures in their designs, and eliminate as many as humanly possible.
How do engineers learn about failure modes? When things fail. It is the embarrassing, tragic nature of the business.
The failure of WTC7 pointed out a new failure mode that they hadn't known previously that was particular to designs like that building.
But it has been known for a long time that fire can and, in the absence of preventive measures, WILL take down steel buildings. Or do you think that they go thru billions of dollars per year in thermal insulation, sprinklers & other measures for the express purpose of protecting the steel from the fire for no reason?
Every once in awhile, as in the case of the Towers & WTC7, a failure progresses to total collapse. And whenever this does occur, your fundamental thesis is completely wrong. It DOES happen as a result of a single component failure. The LAST component before total collapse. Because all the other structural redundancies have already been compromised.
In the WTC7 collapse, there are thousands of components that failed without leading to total collapse. But the building did NOT reach an equilibrium. It was still IN THE PROCESS of total failure.
Loads were in the process of redistributing, metal was in the process of yielding, of creeping, of flowing, etc. Fires were in the process of heating new members.
And when that final collapse began, it DID begin as a direct result of a SINGLE component that failed - whatever it was, it might have been something as simple as a single bolt snapping.
The point is that, between the time the fires started and the building collapsed, the building never achieved a true static equilibrium.
And this simple picture applies to every progressive failure that has ever occurred.
tk
Yet you have no clue (or at least can't explain in a logical manner) why you think what you think is true."Fires were in the process of heating new members"
When i read goofy stuff like that, it makes me spit up the energy drink i am having a sip of.
Those fires were not hot, nor longlasting in any location in that building.
How any sane person can possibly believe a column so big that it is 7 tons per floor in mass(and a big guy couldnt even come close to wrapping his arms around its FIREPROOFED girth)it gives me the willies about the "critical thinking" going on around here
It makes me think of an apt comparison. Holding up a cigatette lighter at an indoor concert, and wondering if that small flame will bring the whole arena crashing down...........................
Yet you have no clue (or at least can't explain in a logical manner) why you think what you think is true.
Your wrong and WE all know why. Education will do that.
"Fires were in the process of heating new members"
When i read goofy stuff like that, it makes me spit up the energy drink i am having a sip of.
Those fires were not hot, nor longlasting in any location in that building.
How any sane person can possibly believe a column so big that it is 7 tons per floor in mass(and a big guy couldnt even come close to wrapping his arms around its FIREPROOFED girth)it gives me the willies about the "critical thinking" going on around here
It makes me think of an apt comparison. Holding up a cigatette lighter at an indoor concert, and wondering if that small flame will bring the whole arena crashing down...........................