Dr. G wrote:...smearograms are our last best hope to figure out what caused the collapse of WTC 7.
I find this a most interesting sentence fragment, coming from you. What I know of you dictates that even fragments are not casually constructed or offered. I also suspect that there is always more an arsenal of analytical skills up the sleeve than meets the eye.
Over here, there are more things going on than being discussed, despite all the words flowing out of this IP address. One of these things is reverse engineering element displacements (by extension, member deformations) from the paltry few illustrations in the NIST report. In showing 3D renderings of their simulations, they have opened the door to at least partial falsification of their model. Having their numeric input and output would be better, but I'm not into that and it's probably not necessary, a few well-synchronized keyframes should do.
One of the first things was digitizing the north face buckle they depict for the debris damage scenario. Pretty damn revealing, it was. One can immediately infer the downward displacement of the roofline at a specific time as demanded by the conformation depicted. From another viewpoint, the observed abrupt initiation and rapid descent of the north roofline has some implications for the lateral acceleration of the buckling hinge, likewise the volumetric displacement of the curtain wall through other members.
It may be possible to construct a 3D map of residuals resulting from the difference between the perimeter shape they predict and the actual perimeter surface over time. NIST has done the equivalent of charting the course and estimated destruction of a hurricane produced by the flap of a butterfly's wings, given only a few snapshots of the butterfly's position at different times. One does NOT need to be schooled and employed in relevant disciplines to rightfully claim that, from a systems theory standpoint, they're asking the public to believe they are modern day Merlins.
