Click Images to Enlarge 1. Top Third
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5. Exiting Debris
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The images show the steel structure of the WTC-1 building and the concrete floors. Colors are not meant to be realistic. We modeled the entire building structure, including the supporting steel below the surface. Figure 1 shows the top third of the model.
The WTC-1 building had an exo-skeleton, a steel structure on the exterior that partially supported the building's weight. The incoming plane cut into that exo-skeleton. Side-by-side we show the facade before (Figure 2) and after the crash (Figure 3) as determined by our simulation. The damaged facade (Figure 3) shows also the debris and dispersing fuel of the aircraft in the interior of the building.
The photo, Figure 4, shows the actual damage to the exo-skeleton at the entrance of the airplane as recorded by an eye witness. The small image is from the web; a larger image is reproduced from FEMA Report 403, September 2002, "World Trade Center Building Performance Study."
Figure 5 shows a side view of the simulated impact. Note the debris and fuel spray exiting the building.
This work has been supported in part by NSF grant DSC-0325227, A. Sameh PI.