Nice work. Except for this: you read what they said about why the buildings collapse. But not the conclusion.
The conclusion was that they were unable to prove that any of that happened with any of their models. And that's what I said. That means what you posted falls firmly in the realm of unsubstantiated hypothesis. Have fun reading the whole report only to end up at the conclusion that they were unable to prove any of it.
Reading comprehension. It's what's for breakfast. Be sure to grab your lunch pail on the way out.
" For studying the impact on a 110-story building by an actual Boeing 767 aircraft, a full-scale test was not feasible. For a test to capture the response of the towers as a system, it would have been necessary to construct a test assembly that included the core columns, exterior columns, floors and hat truss. Even to replicate experimentally the response of the floors near and above the impact zones would have required test assemblies of about 20 stories for WTC 1 and 30 stories for WTC 2. No facility exists to conduct such a test, either with fire or in the absence of fire; and, indeed, such tests are not conducted in current engineering practice.
Therefore, NIST relied on high-fidelity finite element modeling of the aircraft impact event and subsequent fires. The analyses were calibrated against the observed structural response of the towers upon impact (videos, photographs, and physical evidence) and the evolution of the ensuing fires.
NIST did not conduct reduced-scale system-level tests because there are no generally accepted scaling laws that apply to fire propagation, temperature evolution, and structural response.
Furthermore, fire test facilities with the capability to apply arbitrary fire exposures (in contrast to the standard time-temperature exposure) and arbitrary loads to structural components did not exist in the United States at the time of the investigation. Even had such a facility been existent, each large-scale structural fire test would have evaluated only a single set of conditions, e.g., structural system, fire exposure, amount of fireproofing, etc. Even a modest parametric series of such tests would have been prohibitively expensive.
NIST did conduct full-scale fire tests of single and multiple workstations. These tests were of sufficient size to properly capture the combustion physics. These tests established burning histories, mass burning rates, and heat release rates. The results were used to validate the fire dynamics calculations for fire growth and spread (see NIST NCSTAR 1-5E). NIST also conducted full-scale fire tests exposing insulated and bare structural elements to real fires to validate the fire and thermal modeling approaches (see NIST NCSTAR 1-5B). "
So, that's a long-winded way of saying that they weren't able to model the events but did get some good data. However, that's not the end of it. But while I'm here, there's this gem:
"Nearly all fires are limited either by the burning rate of combustible fuel (fuel-limited fires) or by the availability of air (ventilation-limited fires). Many fires that are ventilation limited do continue to burn, with the burning rate determined by the chemistry of the combustion and the rate at which the oxygen arrives. This was generally the case for the WTC Tower fires. Of course, if the rate of air inflow were
too slow (e.g., due to very few broken windows), the limited combustion would not have generated sufficient heat to continue pyrolyzing fuel, and the fire would have gone out. This was not the case on the fire floors in the WTC Towers."
Note where they said that the fires were oxygen limited. Ah, yes. Yes they were. Yet they chose the worst case scenario for the fires, as if they were operating with full oxygen delivery.
Let's poke some more holes:
"Evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent intergranular melting, was readily visible in the near-surface microstructure. A liquid eutectic mixture containing primarily iron, oxygen, and sulfur formed during this hot corrosion attack on the steel… The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified."
Oh really. That doesn't happen in normal fires.
But then, the NIST report doesn't even try to explain the molten metal found at the site, although FEMA found and confirms it.
I'm looking for quotes of the lines of conclusion... this is going to take me longer than I have tonight. It's not like I keep a staff to do this kind of thing. If I'm able I will do that tomorrow.
