photonic writes "After a 3 years of study, NIST finally released its report on the collapse of World Trade Center building 7. The main conclusion is that the building came down due to fire, not due to debris damage or some conspiracy demolition team. The fire started pretty small after the collapse of WTC 1, but was left to burn several floors out completely. The important finding is that the collapse was triggered by thermal expansion of beams, which could detach asymmetrically loaded girders from the main columns. Some limited pancaking of floors than caused lack of lateral support and buckling of a single column. This triggered the failure of the entire core of the building, which finally fell down as a single piece. Crackpot theories can be discussed in the Digg comments, so please limit the discussion to the science here. All documents can be found here, which read like a porn magazine for finite element junkies. Awesome movies are here. And yes, they used Beowulf clusters to do the simulations, some of which lasted for several months." Link to Original Source
This discussion was created for logged-in users only, but now has been archived.
No new comments can be posted.
It is obvious that many of you doesn't take into consideration that most efficient and easy way to collapse a steel structure is to use thermite 'explosive', which doesnt explode at all, in fact thermite generate an extremely powerful exothermic reaction, that can reach temperatures in excess of 2500-3000degrees Celsius.
So there is no need to hear any loud bang at all. In addiction thermite is composed of very easily produceable and transportable materials, ferrous oxide (rust+-) plus aluminium powder, whi
concerning explosion sounds... (Score:1)