Collapsing model

ROTFLMAO ....... LOLOLOL ... a stack of playing cards trying to disprove the demolition facts of the WTC ????

What a joke ........ what an idiot.

Originally posted by inobmaz
ROTFLMAO ....... LOLOLOL ... a stack of playing cards trying to disprove the demolition facts of the WTC ????

What a joke ........ what an idiot.

Are you 12 years old or something?

This is a discussion forum and throwing immature phrases like "ROTFLMAO" and insulting people is out of order. Grow up and stop being so ignorant

Originally posted by inobmaz
ROTFLMAO ....... LOLOLOL ... a stack of playing cards trying to disprove the demolition facts of the WTC ????

What a joke ........ what an idiot.

First of all, I wouldn't use playing cards to prove that WTC wasn't demolished. That would be ridiculous, wouldn't it? what I'm trying to prove (and did), is that even if tower's floors (at top) can support atleast 10 times the mass that is above it, it still can collapse from top to bottom.

Second, I never said that this would prove that WTC towers can destroy as seen by it's own mass. You should read my posts more carefully before calling me idiot, idiot.

( )

My other goas is to make a tower that would carry out all those 5 requirements:

CHALLENGE #1:

Build an upright structure that will undergo progressive collapse.

CHALLENGE #2:

Build an upright structure with a square footprint and an aspect ratio of at least 6.5 (6.5 times as high as it is wide) that will undergo progressive collapse.

CHALLENGE #3:

Build a structure as required by CHALLENGE #2 which, in the collapse process, will throw pieces outward in all directions such that at least 80% of the weight of the materials ends up lying outside of the footprint, but their center of mass lies inside the footprint.

CHALLENGE #4:

Build a structure as required by CHALLENGE #2 which is also capable of withstanding a 100 MPH wind without collapsing. The structure has to be closed in the sense that it cannot allow air to pass through it.

CHALLENGE #5:

Build a structure that meets the requirements of both CHALLENGES #3 and #4.

Haha I don't wonder why ur ATS Points are negative...

Originally posted by msdos464
Haha I don't wonder why ur ATS Points are negative...

And that's only one of his many accounts..

Keep up the good work anyway buddy, you're doing good. It's nice to see someone using some initiative whatever the outcome.

Originally posted by msdos464
what I'm trying to prove (and did), is that even if tower's floors (at top) can support atleast 10 times the mass that is above it, it still can collapse from top to bottom.

You only proved that this could be the case if there was absolutely no lateral strength behind any of the columns. Like, column stacked upon column, rather than bolted and welded together, as they actually were.

Bolts and welds are not as strong as a continuous piece of metal by any means though, joins of any kind are always the Achilles heel of any construction. The principle dos had demonstrated, in my humble opinon, is still relevent as
1) It reinforces my ideas (LOL)
2) because given that the joins will have been weakpoints, they would be the first to fail as the (non) joins in the model did. A weld is always a weakpoint and with bolts you are relying on the bolts themselves.

Originally posted by AgentSmith
A weld is always a weakpoint and with bolts you are relying on the bolts themselves.

You are correct and incorrect at the same time. Welds are definately weeker. Bolts get trickier. It depends on what type of force is applied. They will be weeker in shear definately. The thing with bolts though is if you add more than one, you get the advantage of that bolts strength multiplied by how many bolts are in the joint. This is advantageous up to the point where the bolt holes are too close together to weeken the steel plate where the bolt holes are. Make sense?

Dos's model would represent steel beams stacked onto each other with absolutely nothing holding them together for lateral strength.

The WTC Towers were built to withstand hurricane winds, up to around about 100 MPH if I'm not mistaken.

Even if you think the bolts and welds were the failure, there would still be significant lateral resistance. Even if there was the alleged buckling, and even if it was a buckling of a majority of perimeter columns and somehow caused global collapse, there would still be a loss of collapse velocity along the way from lateral resistance alone because of (a) the strength of hundreds of columns and therefore hundreds of bolts and welds and etc., and (b) the massive amount of debris being ejected outwards was not exactly contributing additional loads to lower columns that were built to withstand higher loads than upper floors.

It takes weight to cause bolts to fail. Bolts won't fail without force being applied to them. It would take a great, directed force to cause all of the bolts on a single floor to fail simultaneously (not to mention a miracle), and yet this is what must have happened because the towers fell symmetrically and did not lopside. But the driving mass was losing lots and lots of material off the sides of the building, until it didn't really exist anymore as any single piece of building, and yet you still apparently had bolt failures at the exact same speed and symmetry that you had earlier in the collapse. But from deflected, dissociated material? I seriously doubt it. That just reeks of explosives to me. Do you get where I'm coming from with this?

Griff
Make sense?

Yes.

And in any case, welded, bolted, riveted, glued or any other form of actual physical connected columns will be much more resistant to collapse than carefully balanced houses of cards.

Can we agree on that, Agent Smith?

[edited to include quote]

[edit on 2-3-2006 by Lumos]

Of course, and I see your point bsb, but there would be great forces involved with the top floors collapsing - the ony real issue I can really ackowledge based on my understanding is perhaps considering that the top floors fell in such a consistant manner based on whatr you are saying.

Bolts and welds are not as strong as a continuous piece of metal by any means though, joins of any kind are always the Achilles heel of any construction. The principle dos had demonstrated, in my humble opinon, is still relevent as
1) It reinforces my ideas (LOL)
2) because given that the joins will have been weakpoints, they would be the first to fail as the (non) joins in the model did. A weld is always a weakpoint and with bolts you are relying on the bolts themselves.



This can be true but is not necessarily so in practice. Because these phenomena of stress concentration are understood consideration is made at the design stage.
Welds for example are not likely to fracture at the weld site, but if the failure can be attributed to poor welding practice or design the fracture is more likely to be at the junction between weld and parent metal within the heat affected zone, if one remains. Undercutting or other such weld flaws would exacerbate this situation.
Design can be made to allow double or even triple shear on the same bolt. So it is a simple matter to design to allow for these factors.

However you are correct in your highlighting of the column connections as being failure sites, since visual evidence indicates these failures and what is important with regard to the towers collapse is precisely the modes of failure and how they could have come about.
The difficult part comes in figuring out how the available potential energy could overcome the strain energy of the lower sections, or even overcome enough of the strain energy deficit to even allow a force to act on the connections.

Gordon