Saturday, December 17, 2005

NIST's Evasion

9-11 Review

NIST's Evasion
NIST (National Institute for Standards and Technology) was given a budget of tens of millions of dollars to study the collapses of the World Trade Center skyscrapers. Yet it avoided that charge in any meaningful sense. Its final report admits that it didn't even attempt to model the collapses.
The first critique to thoroughly expose NIST's evasion of its task of investigating the collapses was provided by Sami Yli-Karjanmaa on July 14, 2005. The following excerpt includes more that half of the brief critique.
e x c e r p t
title: NIST and the WTC: 'Science' at the Service of an Empire
authors: Sami Yli-Karjanmaa
The first of the specific objectives of the NIST study was to "[d]etermine why and how WTC 1 and WTC 2 collapsed following the initial impacts of the aircraft and why and how WTC 7 collapsed." [3] These questions are not answered for simple reasons:
Incredibly, the progressive collapse of the Twin Towers has been left out of the computer models used: "The global models of the towers extended from several stories below the impact area to the top of the structure." [4] Thus the structurally intact floors 1-91 of WTC 1 and floors 1-77 of WTC 2 were excluded from the so called "global" models of the towers.
Correspondingly, the temporal dimension was cut short as well: NIST gave itself the task of finding out "[t]he probable sequence of events from the moment of aircraft impact until the initiation of global building collapse." [5]
...
In other words, "Even without the modeling of the progressive collapse we had to postpone the publication of the reports four times so we just didn't have time to do that. And besides, the lower parts of the buildings simply did not slow down the collapse, as everyone could see on TV, so why bother?"
In summary: The reports by NIST say nothing about how -- and if! -- the collapse was able to progress through dozens and dozens of structurally intact floors without being stopped. If no external energy was available e.g. in the form of explosives, this would have been the opportunity to show that no such energy was needed. On the other hand, if some unaccounted-for energy broke the supporting structures enabling the collapse to progress with the speed it did, there would have been many good reasons not to try to model the impossible, ie. a purely gravitation-driven collapse. Stopping the analysis early enough also saves NIST from trying to explain the symmetricality of the collapses (despite non-symmetrical impact damage and fires), the almost complete pulverization of non-metallic materials as well as the extremely hot spots in the rubble. These remain as inexplicable by the official story as they have ever been.
One appendix of project 6 includes an interesting analysis of a dropping floor. [8] According to the results, however, temperatures of 400 to 700 ºC are needed in order for the collapse to be initiated. Unfortunately, the destruction of evidence at Ground Zero was so complete that NIST can now only say that the steel components recovered demonstrate that there was "limited exposure if any above 250 ºC." [9]
NIST's collapse creed, repeated eleven times with identical wording (and once with a slightly different one) in the report of project 6 dealing with the collapse sequences, is this:
" The change in potential energy due to downward movement of building mass above the buckled columns exceeded the strain energy that could have been absorbed by the structure. Global collapse then ensued." [10]
In other words: "Once the top started coming down, it was so heavy that the damaged columns could not stop it. Neither could the undamaged columns of dozens of floors do that, it seems. But we didn't need to model that for we've all seen that down it came."
Thorough, open, independent?
References: (75 kB), p.3 http://wtc.nist.gov/pubs/NCSTAR1-6ExecutiveSummary.pdf (1.4 MB), p. lxii[6] http://wtc.nist.gov/pubs/NISTNCSTAR1-6DDraft.pdf (19.4 MB), p. 5] http://wtc.nist.gov/pubs/NCSTAR1-3ExecutiveSummary.pdf (52 kB), p. xlisite: www.saunalahti.fi/wtc2001/ page: www.saunalahti.fi/wtc2001/nistcomm.htm
Later, Jim Hoffman wrote a critique of NIST's report, which, although far more detailed than Yli-Karjanmaa's, makes essentially the same central point.
e x c e r p t
title: Building a Better Mirage: NIST's 3-Year $20,000,000 Cover-Up of the Crime of the Century
authors: Jim Hoffman
To shield the reader from the evidence of controlled demolition, NIST fills hundreds of pages with amazingly realistic plane crash simulations, tedious details about fire tests and simulations, and long lists of recommendations for improving building safety. It calls its event narrative of each Tower, which starts with the jet impact and ends at the point that "collapse ensued," the "probable collapse sequence," but it is neither probable nor a collapse sequence.
NIST's misleadingly named "probable collapse sequence" is a mirage, masking the explosive reality of the collapses with a cinematic account of the crashes and fires. NIST's theory stops at the moment that the "upper building section began to move downwards," thus avoiding the longer timeline of the truss-failure theory and any overlap with the time span in which the demolition-like features appear. Despite NIST's theory being even more incredible than its predecessors (with spreading "column instability" triggering "global collapse" in an instant) it works better as a mirage because its timelines stop short of the collapses.
NIST's Report states that its first objective is to "determine why and how WTC 1 and WTC 2 collapsed." The Report does not fulfill that objective, and hides that failure with misleading headings and disproportionate, misapplied technical detail. Its authors should admit that they have failed to explain why and how the Towers collapsed, and should call for an investigation that will address rather than avoid the issue.
site: 911research.wtc7.net page: 911research.wtc7.net/essays/nist/
Hoffman's critique points out that NIST's Report, while avoiding even claiming to model the collapses, implies but does not show that it modeled the onsets of the collapses. The Report's section entitled Results of Global Analysis" describes the tops of the Towers first tilting and then moving downward as intact blocks, but there are no images in the Report of its computer models showing this behavior. The New Civil Engineer (NCE), an engineering trade journal based in the United Kingdom, published an article highlighting NIST's failure to publish visualizations of its alleged analysis of "collapse initiation."
e x c e r p t
title: WTC Investigators Resist Call for Collapse Visualization
authors: Dave Parker
WTC Investigators Resist Call for Collapse VisualisationWORLD TRADE Center disaster investigators are refusing to show computer visualisations 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 investigators. The collapse mechanism and the role played by the hat truss at the top of the tower has been the focus of debate since the US National Institute of Standards & Technology (NIST) published its findings (NCE 22 September 2005). NIST showed detailed computer generated visualisations of both the plane impacts and the development of fires within WTC1 and WTC2 at a recent conference at its Gaithersburg HQ. But the actual collapse mechanisms of the towers were not shown as visualisations. University of Manchester (UK) professor of structural engineering Colin Bailey said there was a lot to be gained from visualising the structural response. "NIST should really show the visualisations, otherwise the opportunity to correlate them back to the video evidence and identify any errors in the modelling will be lost," he said. University of Sheffield professor Roger Plank added that visualisations of the collapses of the towers "would be a very powerful tool to promote the design code changes recommended by NIST." NIST told NCE this week that it did not believe there is much value in visualising quasi-static processes such as thermal response and load redistribution up to the point of global collapse initiation and has chosen not to develop such visualisations. But it said it would 'consider' developing visualisations of its global structural collapse model, although its contract with the finite element analysis subcontractor was now terminated. A leading US structural engineer said NIST had obviously devoted enormous resources to the development of the impact and fire models. "By comparison the global structural model is not as sophisticated," he said. "The software used has been pushed to new limits, and there have been a lot of simplifications, extrapolations and judgement calls. This doesn't mean NIST has got it wrong in principle, but it does mean it would be hard to produce a definitive visualisation from the analysis so far."
site: http://www.nceplus.co.uk/ page: georgewashington.blogspot.com/2005/11/professor-jones-is-right-government.html

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