Reply #98: I can't find the previous conversation

[AZCat]

Advanced Search is disabled right now, so I can't find the previous conversation I had regarding buckling and the WTC supports.

Buckling is when a beam that is long compared to it's width and height is subjected to a large enough axial load that it "buckles". An easy example of this can be seen by pushing on the opposite ends of a piece of spaghetti. The spaghetti doesn't fail due to compression, it "buckles" - or bows out - and then fails.

The floors all provide horizontal support for the main load-bearing columns in a building - the floors prevent the columns from behaving as the piece of spaghetti in the above example. If you had a friend place his or her hands around the piece of spaghetti and prevent it from buckling, it would fail at a much higher load than without your friend's hands in place.

In our previous conversation, the poster and I discussed the possibility that the impact of the crash of the aircraft somehow destroyed the supports for the load-bearing beams for one or more of the floors. This would double (or triple) the unsupported length of the beam and reduce significantly the load it could carry before buckling (and subsequently failure).


Does this help? I will find the thread I mentioned whenever we get Advanced Search back - probably sometime tonight.