there is a resistance in every floor.
No. There isn't. Once a column fails it provides NO resistance. And since it takes no time to fail... there is essentially no difference between sequential failure and free fall. It's simple physics.
the speed of gravity is the speed of gravity I don't care if it's an apple and orange
You should care. Because you're apparently just parroting what others say, rather than knowing what you're talking about.
and another thing if the melting theory that you talk about is true the top of the building would fall to 1 side not straight down.
No it wouldn't. The table I posted shows how much strength steel loses as a function of temperature. Steel will lose over half it's strength before reaching 500C. If you can't understand that from the table I posted, you should try to learn more before buying into any more theories.
The building would NOT fall sideways. It's ignorant to think it would. To fall sideways it, several things would have to be true. First it would have to fail first at the bottom, rather than the top. This is clearly not the case.
Second the beams of the structure would have to fail before the columns. This is never going to be the case as columns are inheirently weaker because they don't fail in bending.
Finally, one would need a force applied to the top in the sideways direction. There is nothing pushing the building sideways.
If you believe in the "pancake theory" you clearly believe that the building fell floor-by-floor. That would mean it would fall vertically by overload of the floor above. Clearly this is the case.
Failure of the columns by heat has nothing to do with with the direction of collapse, though I'd love to hear your explaination of how it could.
there is no way you are a structural engineer no way.
Clearly you aren't either. Do you even know what Castigliano's Theory is? Tell me do columns fail in bending? Do columns yield before failure? Or do they fail all at once -castastrophically? You're right, tho. I'm not a structural engineer, I'm hold a ME degree. But all of the above are basic engineering concepts that are taught to civil and mechanical engineers in sophomore year. It's pretty clear you're no structural engineer either.
I'm out I'm done
Thanks. You've proven my OP.
This post was edited on 1/26 at 12:50 pm