Bullshit. If you know so much about structural engineering then explain why an object the size of the plane would leave a hole much smaller than itself with the surrounding wall smooth and showing little signs of impact? I am amazed at how fucking stupid you'd have to be to believe it. You claim to be a "structural expert"?? How's that? What's your background?
Again explain it. If you give a plausible explanation and convince me please do.
In the case of the WTC we see a plane cut into the building like a knife through butter. It is cutting through steel columns. Now in the Pentagon example it just bounces of the building and the nose leaves a car-sized hole? There is no way in hell that a plane would not have made a huge opening in the wall equal to or greater than it's footprint when travelling at 500 mph.
First, a little about myself... I have a mechanical engineering degree from one of the better science colleges on the east coast. I have a minor in industrial engineering, with a focus on structrual design. I work for a garment manufacturer in midtown Manhattan designing floor plans and head the facilities and security group. I'm also 39, like long walks on the beach, cooking with my wife.,.. etc.. hahaha.
Answer your QUESTION IS Easy. Density. Concrete is some 12 feet thick in places in the pentagon, reinforced by rebar and I believe a layer of either lead or steel plating TO SHIELD high level gov't people in the event of a nuclear attack. You may not know that fact because it is not exactly broadcast out there. As I stated before my father in law worked there in the 60s. It is layered as one solid object in simple terms. This building was constructed during the cold war.
The WTC was a hollow steel structure designed to act like two cylinders, One inside othe other. This was because they wanted an open floor concept; no interior columns. This design, one that was very strong, put the steel columns on the outside of the structure, with the center "tube" housing the stairways and elevator shafts. Sort of like a celery stalk. Anyone (like me) who has had to design floor plans for offices and distribution centers (in Long Island City Queens for example)
), within existing structures know the inherent obstructions interior columns pose. Now, the first mistake you are making is assuming the two buildings are the same, or function the same. I know this by your statement above: "is no way in hell that a plane would not have made a huge opening in the wall equal to or greater than it's footprint when travelling at 500 mph." You are taking this as if they are both the same building. in terms of structure, freedom of movement, and design requirements. The Pentagon was designed as the military nerve center for the USA so it will have inherent design characteristics for security. The WTC was designed as a state of the art office tower and not designed to fend off an attack. Although they did design it to withstand a direct hit from a 707. But your comparo is apples to oranges.
Getting to the small hole... The plane generally hit nose-cone first. This would be considered a point load. Thus, the impact from the plane was at its most severe at the center of the impact. This was at the greatest point of absorbson; Fo = mass x velocity. The wings, ralative to their density v. the concrete structure basically bounced off, and disintegrated due to the velociity is impacted the concrete. This building is just simply designed to take a direct hit. The WTC, although designed to take a direct hit from a much smaller aircraft at lower speeds, did a great job at holding up so some 20k people could get out. Then the fire took over, weakening columns, and collapsed top down. I know it may be too difficult to understand by someone like you who already made up their minds regardless of any facts that discredit yours.
