Can any of you show steel shattering when gently heated to far below its melting point?
I'm not going to waste any time with you.
Steel doesn't shatter under any of the conditions pertinent to 9/11.
Steel was not turned into dust. Ceiling tiles, wall boards, and a small percent of the concrete was.
ALL of the steel was accounted for. As steel girders. It was loaded onto trucks, that were weighed, and transported to Fresh Kills land fill.
Steel can fail in a number of ways, but it is always due to stress. The specific stress level is variable, depending on the many factors including type of stress (tension, compression, shear, etc), temperature, type of steel, etc.
The fire temps did not DIRECTLY weaken the steel enough to cause the collapse.
Creep vs stress level vs temperature
Journal of Engineering Mechanics ASCE , Vol. 134 (2008)
What Did and Did not Cause Collapse of WTC Twin Towers in New York
Zdenek P. Bazant, Jia-Liang Le, Frank R. Greening and David B. Benson
BLGB said:
Page 2:
"But are high steel temperatures really necessary to explain collapse?
Not really.
... The tests by NIST (2005, part NCSTAR 1-3D, p. 135, Fig. 6-6) showed that, at temperatures 150° C, 250° C and 350° C, the yield strength of the steel used in the fire stories decreased by 12%, 19% and 25%, respectively.
Reducing the yield strength of those columns by that amount is not sufficient to cause the collapse. Reducing the yield strength of an otherwise intact, aligned structure is typically what happens in a fire. This is why fire alone does not usually cause steel buildings to collapse. (Aided by insulation & fire fighting, of course.)
However, in the case of the WTC, reduced yield strength of an otherwise aligned building is not all that happened. This is why the physical damage of the planes' impacts is crucial to understanding what did happen.
The fire temps did INDIRECTLY lead to the collapse of the buildings. The factors that led to the excessive stress level was creep, which has been proven to happen, when the steel is exposed to high stress levels, at very low temperatures (depending on stress levels, as low as 150°C.) The physical damage led to excessive stresses, which led to creep, which led to higher stresses, which led to more creep, which led to even higher stresses, etc. A fatal positive feedback loop.
BLGB said:
... These effects of heating are further documented by the recent fire tests of Zeng et al.(2003), which showed that structural steel columns under a sustained load of 50% to 70% of their cold strength collapse when heated to 250° C.
... Nevertheless, it can easily be explained that the stress in some surviving columns most likely exceeded 88% of their cold strength S0 . In that case, any steel temperature ≥150° C sufficed to trigger the viscoplastic buckling of columns (Bazant and Le 2008). This conclusion is further supported by simple calculations showing that if, for instance, the column load is raised at temperature 250° C from 0.3Pt to 0.9Pt (where Pt = failure load = tangent modulus load), the critical time of creep buckling ... gets shortened from 2400 hours to 1 hour ...
Therefore, to decide whether the gravity-driven progressive collapse is the correct explanation, the temperature level alone is irrelevant (Bazant and Le 2008). It is meaningless and a waste of time to argue about it without calculating the stresses in columns. For low stress, high temperature is necessary to cause collapse, but for high enough stress, even a modestly elevated temperature will cause it."
You've demonstrated zero understanding of rudimentary mechanical engineering or material science.
You should stick to performance art & coloring books.
Which is exactly what I expect all this nonsense, leading up to your alleged Dec. 1 "revelation" is all about.
Nothing of any substance. Just frivolous theater and self-indulgence.
And massive disrespect to many thousands of serious people who gave great effort & great service to this country in figuring out what really happened on 9/11.
