Has Derek claimed to be an expert in engineering? I don't remember seeing that.
No, Derek did not claim that. I worked for the gov't in the Navy. No expertise needed for that job, none aquired either. I worked in steel fabrication (pressure vessels), foundry and construction. No expertise needed for those jobs, none aquired either. Eventually I had a brief chance to go to school when I was 27, graduated @ 31...no expertise aquired, but made it through a pretty tough program.
I'm no expert, and never will be, is there such a thing anyway? I do, however, have questions hitherto under-answered or outright avoided like the plague.
They go to the root: could thermal expansion do that to WTC 7? Especially the awkward way NIST has it framed:
“At > 300o C in the shear studs, differential thermal expansion of the floor beams and floor slab resulted in significant [whatever significant means in the land of NIST] shear studs and caused them to fail” – NCSTAR 1-9, p. 473
Yet they get this "differential" through heavy model manipulation. If we ever get there, I'll be more than happy to point these NISTisms out.
or even better:
“Primarily for the east tenant floor, when a floor beam thermally expanded, the beam displaced the girder at the interior end of the floor beam but did not displace the exterior frame at the other end of the floor beam.” - NCSTAR 1-9, p. 526.
If the beams are unrestrained at one end, how can they develop the compressive force necessary for buckling to occur? TFK? Can you at least get this one straight?
or even better still
“Many of the east floor beams on Floors 12, 13, and 14 failed by buckling, as shown in Figure 11-27 and Figure 11-35” – NCSTAR 1-9, pp. 526-27
How can the beams push the girder laterally if they have buckled in compression?
TFK? Anyone?