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Researcher
Mike Kennedy fires the air gun on NIST's Kolsky Bar Tester. This
device measures the mechanical behavior of steel from the World
Trade Center under stresses similar to those that resulted from
the aircraft impact with the buildings.
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NIST
researcher Mike Kennedy aligns a high-speed temperature sensor on
a Kolsky bar apparatus used to measure the mechanical behavior of
steel. The test sample from recovered World Trade Center steel is
just visible between the two bars in the center of the picture. At
high rates of deformation, heat is generated. About every millionth
of a second, this instrument measures changes in the average temperature
across an entire sample. |
NIST
researcher Bill Luecke checks the calibration of a contact extensometer
used in the high-temperature mechanical testing system pictured here
to assess (at temperatures from room temperature to well over 1,000
degrees Celsius) the strength and ductility of the steel used to build
the World Trade Center. |
NIST
researcher Steve Banovic uses an optical microscope to examine the
microstructure of steel from the World Trade Center. This information
will help identify the type and quality of steel used. Pieces from
actual WTC beams are visible on the right. |
NIST
researcher Richard Fields adjusts a dial gauge on one of several creep
testers that will be used to evaluate the high-temperature, time-dependent
mechanical behavior of the steel used to construct the World Trade
Center. |
