It illustrated nothing of the sort. It did illustrate exactly what I alluded to though, as do the vast majority of your worthless posts.
Are you saying that the lower 90 stories of the north tower were not destroyed because the upper portion fell on them? I am not going off on semantic games to argue about what word to use to describe that supposed destruction. That is pseudo-intellectual bullsh!t for morons. Or people who want to deliberately cause confusion. psik
I'm saying there's a difference between crushing and buckling. It's a big difference. It's not pseudo intellectual. It's how to accurately describe the mechanics of a structure. If you had watched that buckling video I gave you, if you had reviewed the MIT course I linked you to, if you had taken even a half a second to look up buckling, slenderness ratio, or any of the concepts that have been introduced to you, you would have known that already.
Maybe part of the reason you believe in conspiracy theories is because you deem factual, theory shattering evidence as "semantics". Instead you should learn the differences between them, and you might possibly see things a bit more accurately.
So use whatever word you want. I don't give a damn. Are you saying the lower 90 levels were "destroyed" as a result of the upper portion falling on them? Or do you want to use some word other than "destroyed"? psik - - - Updated - - - What have I said about conspiracy theories? Are you saying 19 Arabs hijacking planes on the same day was not a conspiracy? psik
The lower part of the building was destroyed by the upper part that dell on them. The problem that a lot of people have here is that it did not involve "crushing" in the normal sense, for the most part. "Crushing" did play some part in the initiation of collapse, in that it destroyed parts of the core and perimeter columns in order to drop massive debris onto the floor slabs below. This destroyed the structural integrity of the remaining core by removing some of the cross-bracing within the core. The mode of destruction for most of the building was the removal of the rest of rhe floors. Once a floor slab was removed from its mounts, it became a kinetic object with a mass equal to its own orginal mass, plus the mass which had fallen on it. Part of the problem with any model using such materials as tooth picks or match sticks is that these materials do not behave as steel would. Wood, being fibrous, is very resilients and attenuates the impact by giving gradually. Steel tends to break rather quickly once sufficient force is applied, and to break cleanly. You can see an illustration of this in examining steel plates and wooden boards into which the same caliber of bullet has been fired. Some of the fibers of a wooden board will spring back into the hole after a bullet has passed through. This should tell you that it is at least applying some friction to the bullet as it passes, whereas once the initial resistance of steel has been overcome, it ceases to offer any more. The problem that this presents in making an accurate physical model of the collapse is that it is difficult to scale down a steel structure like the floor slabs so that it will fail in the same manner. It would involve first producing some steel foil and tiny pins to hold the scaled-down trusses to brackets firmly attached to scaled-down steel perimeter columns. I am sure that the technology exists to produce such materials, but it would be very labor-and-capital intensive to do so. This is why I suggested using dry pasta. Once it reaches over-load and fails, it just totally fails and starts accelerating downward without resistance until it reaches the next floor.
"Destroying structural integrity" by applying force from above can't possibly be "crushing". Word game bullsh!t. psik
I am saying that there was very little actual "crushing" involved. Most of it was the "crush-up" phase of Bazant-Zhou. the damage to the core below the point of failure mostly weakened it so that it fell rather quickly due to buckling after the floors were stripped of.
Try to keep up. We're talking about the mode of destruction. I'm not the one here trying to play word games because you got caught in a factual error. The steel columns did not crush. They buckled. http://www.structures.tcaup.umich.edu/lectures/17_04_01_13_Steel_Columns.pdf
Because the top of the north tower had to be weaker and lighter than every segment below of equivalent height. The Conservation of Momentum combined with the energy required to destroy the supports would absorb the kinetic energy of the falling mass. Where is the experiment demonstrating even 90% collapse? psik
Talking about an individual column buckling for a detailed analysis of that column is fine. When you have 47 columns connected by horizontal beams every 12 feet you are talking about a structure. Connections in the structure can break which would not be buckling. So saying "crushed" when referring to all of the different thing that might happen in the destruction of a STRUCTURE is perfectly reasonable. Bolts being pulled apart is not buckling. psik
Yeah, that's shearing. It's not crushing. The steel in the tower did not crush. Concrete in the tower did crush, but I fail to see how that supports your model's crush mode of failure. The concrete in the tower was not holding the whole building up. It was only holding up 1 floor worth of load.
The load of the top mass only has to destroy 1 floor of support at a time, and the energy required is only the energy required to buckle a floor, not crush it. By the way, where's your experiment proving that buildings can't collapse? Does your building stand at all without your "trick" of overcoming the problem of slenderness instability with a thick wooden dowel? Your collapse is 0% collapse with that dowel still in place.
You pretty much FAIL since you haven't built a model coming anywhere near complete collapse. But neither has anyone else. Whether it is buckling or shearing or any other word you prefer they all require energy which can only come from the kinetic energy of the falling mass therefore it must SLOW DOWN. Having to repeat the process over multiple levels means it arrests. And whether the words buckling, shearing or crushing are used to refer to what happens to the STRUCTURE makes no difference to the realities of the net result of the physics. psik
Again, are you arguing that a building can't collapse? The words are important because they describe different properties of materials. It takes different amounts of energy to shear, crush, or buckle any specific member. If you say something crushed, it certainly is a different net result than if it buckled, or if it sheared.
You're totally WRONGthe top of the tower was hammer,that gained weight and speed as each floof collapsed.. I need no 'experiment' with bogus washers and paper loops to tell me that.
So doesn't it take different amounts of energy depending on the thickness of the steel? Won't that affect the total weight of steel on each level? So when have you asked about the tons of steel on each level? We do know every level had to be strong enough to support all of the weight above at a minimum. So that is how my model with paper loops is built. It comes nowhere near complete collapse in two drops. So where is the model that does? Are you saying no engineering school has had enough time to do any tests? Of course after this long they would look ridiculous if they admitted tests were needed. psik
Not A BUILDING. A building over 1000 feet tall being collapse by the free fall of less than its top 15% for a distance of less than 24 feet. Shouldn't a simulation removing 5 stories, 91 thru 95, allowing the fall of the top 15 stories be easy enough to do, considering that Sandia Labs simulated 25,000 mph meteor collisions before 2001? The building collapse would be less than 300 mph. psik
Yeah, the nation that put men on the Moon has gotten so SCIENTIFIC in recent years. ROFL The Conservation of Momentum is just irrelevant trash. Talk is so much more impressive than experiments. psik
That's about as much of a response as you can come up with. Physics cannot tell when it is an experiment versus when it is practical engineering. It works the same way. psik
