Using the Signature
Technologies SA-2000 Statistical
and an exclusive algorithm solely licensed by ST, one can calculate the work hardening
coefficient on drawn panels or other components.
Technologies has cooperatively developed with Ford
Motor Company a means of determining percentage variation of material
Work-hardening coefficient (N-factor) away from nominal in cases where a free
stretch draw is made by measuring the force during the draw and post-processing
the data with algorithms developed and patented by Ford
Motor Company. The features
in this application can detect wrinkles, tears, and monitor panel work hardness.
|In practice, one ST feature called "Ratio" is taken
at the beginning of the draw process, and another "Ratio"
feature is obtained later in the draw, well up the force slope.
ST processes are used to eliminate the draw ring backpressure so
that only the draw forces are considered. In the screen shot to
the right the first feature in the ratio is established. Then
another feature is established in the lower screen shot.
|The system works by post processing the returns from the
"Ratio" features with the patented Ford algorithm to discern
changes in the amplitude, and the slope of the signature. Note the placement of the Ratio Features on the forming
The screen capture
below illustrates variations of the work-hardening coefficient in fractions of a
percent from nominal.
module can handle measurement inputs in groups of 8 up to 56 total points.
Technologies can supply a wide variety of solutions to various
manufacturing process problems dealing with measurement, verification of
properties, tool condition, and machine health. We can also “close the loop” by performing process
adjustments in response to specific variations in force, location, or shape of
the work piece, as well as more simple controls which can track and reject
specific parts which don’t meet specific quality criteria.
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