Something just came to mind that I cannot explain. Maybe someone with structural engineering skills kan explain this to me.
According to NIST, as far as I’m right here, part of the collapse of the twin towers was the fact that the floors sagged due to heat, and this pulled in with considerable force on the outer columns.
Can someone please explain to me how a sagging (softer) floor can pull more inwards on a perimeter column than a straight one? We are not adding any force to the floor, it just expands as it is no longer as rigid. The load on the point where it is connected to the perimeter column must be the same.
Of course it would be different if the sagging was due to added weight (downward force) to the floor, but this is not the case.
If i hang a narrow line between two small trees and I grab onto it and hang, it gives way and there is some pull on the trees as well as some sag in the line. If I do the same with a thicker line it does not give way that much, but shouldn’t the pull on the trees be the same? They are supporting the same weight. (Mine)
I cannot wrap my mind around this theory. I bet it has something to do with vectors though 🙂
Help