Q24 on Feb 13 2008, 12:49 PM, said:
“Comparing Figure 7-5 and Figure 7-20, it can be concluded that the overall agreement with the observed damage to the north wall was good for the base case and the more severe case, with the base case analysis providing the better match to the observed damage.”
We were discussing the impact hole in the south wall, not the north.
“WTC 1 and WTC 2 global models were subjected to Case B and Case D aircraft damage and fires, respectively.”
The reason NIST give is that other structural responses (which can only mean the bowing and actual collapses) did not match with Case A. Now, we have the impact damage cause and effect validating Case A based on visual incontrovertible evidence, whereas cause of the bowing and actual collapse supporting Case B are based on pure speculation, ie we cannot see what was happening inside the Towers. I will take the provable Case A over the speculative Case B every time.
The best the official story could argue here is a compromise between Case A and Case B. Then I still want to know why NIST straight out used Case B for the collapse analysis. That is Case B that is farthest from a match to observable evidence. Altogether this just amounts to NIST fitting theories around events in spite of the evidence.
I think you are confusing the Case A/B impact damage and the Case A/B fire model. Read it all again and you will find that the Case A impact damage and Case B fire model were the ones that were eventually used.
I find the NIST collapse explanation perfectly reasonable. It does not conflict in any way with my knowledge of how structures behave. I have yet to see any reason at all in your over-elaborate CD theory.
You keep ignoring the damage to the structure. If, say, 10% of the columns are damaged, then the remaining ones are carrying an average of 11% more load. Most of this load will be on the columns adjacent to the damaged ones, which can well be carrying 30 or 40 % more load. If you want the exact figues, I suggest you ask NIST, as they are the ones who did the calculations. You keep saying "1%", but this is totally misleading.
You are the one who is contradicting Newton. As the collapse progresses, the lower block is impacted by the original upper block plus all the debris from the destroyed floors that were originally part of the lower block. Whether these floors are intact or damaged, they still have momentum, they still cause damage, you cannot just attempt to ignore them.