NIST and the Computer Models

“World Trade Center disaster investigators [at NIST] are refusing to show computer visualizations of the collapse of the Twin Towers despite calls from leading structural and fire engineers, NCE has learned. Visualisations of collapse mechanisms are routinely used to validate the type of finite element analysis model used by the [NIST] investigators.” Parker, Dave. "WTC investigators resist call for collapse visualisation," New Civil Engineer, October 6, 2005.

“The Investigation Team then defined three cases for each building by combining the middle, less severe, and more severe values of the influential variables. Upon a preliminary examination of the middle cases, it became clear that the towers would likely remain standing. The less severe cases were discarded after the aircraft impact results were compared to observed events. The middle cases… were discarded after the structural response analysis of major subsystems were compared to observed events.” NIST, 2005, p. 142; emphasis added.

“The more severe case… was used for the global analysis of each tower... To the extent that the simulations deviated from the photographic evidence or eyewitness reports [e.g., complete collapse occurred], the investigators adjusted the input, but only within the range of physical reality. Thus, for instance… the pulling forces on the perimeter columns by the sagging floors were adjusted...” NIST, 2005, p. 142; emphasis added.

“The software used [by NIST] has been pushed to new limits, and there have been a lot of simplifications, extrapolations and judgment calls.” Parker, Dave. "WTC investigators resist call for collapse visualisation," New Civil Engineer, October 6, 2005.

Someone has apparently filed a FOI request for these models and has recently posted the following on this site:

http://razor.occams.info/nist-wtc/

“As an interested citizen, the son of an engineer, and a very-part-time programmer at a structural analysis software company (LARSA) which happens to be similar to one of the applications NIST used in their analysis, I wanted to get a peak at the computer models used. I'm no conspiracy theorist, but I do like to go to the source when there's a debate.

In late September 2006, seeing that NIST had not posted their computer models publicly, I sent a Freedom of Information Act (FOIA) request to NIST asking that they make the files available to me. (I was not the first to do so, but at least the first to make it to the end of the process---thanks to the advice from the previous attempter---and post the files publicly.) Our government has very fortunately committed itself to making its records public when there is no compelling reason otherwise. In late April 2007 I received a CD from NIST containing the SAP 2000 (input) model files they created. (They used other programs and have other models. Since I was only familiar with SAP 2000 models and wanted to narrow the scope of the request to make it more likely to be filled in a timely manner, I only requested the SAP 2000 files.)”

The author of this site also notes: "The files from NIST were in the binary SAP 2000 project file format. These are completely no use to you unless you have a recent version of SAP 2000 (8.3.3 or later)."

The files are available at this site:

Original SAP 2000 .sdb Files from NIST:
Floor_75_B_09_Jul_04.zip 948K
http://razor.occams.info/nist-wtc/files/Floor_75_B_09_Jul_04.zip

Floor_96_A_14_Jul_04.zip 4.3M
http://razor.occams.info/nist-wtc/files/Floor_96_A_14_Jul_04.zip

TowerA_02Sept04-SDB.zip 8.1M
http://razor.occams.info/nist-wtc/files/TowerA_02Sept04-SDB.zip

TowerB_02Sept04-SDB.zip 7.3M
http://razor.occams.info/nist-wtc/files/TowerB_02Sept04-SDB.zip

It had occurred to me before to file a FOI request for these files. Has anyone else considered doing this?