MTS Multipurpose Elite - Manual (Page 244)

Parameters
ForceArray - The force array used to determine end of the Yield Point Elongation region.
DisplacementArray - The displacement array used to determine end of the Yield Point Elongation region.
YPEStartIndex - The index associated with the start of the Yield Point Elongation region.
PeakTolerance - The percentage drop from the of the peak force that must occur before starting the search
for the zero slope region of the curve.
ZeroSlopeSegmentLength - The percentage of the total points used to determine the zero slope region.
MaxSlopeSegmentLength - The percentage of the total points used to determine the maximum slope
region.
Unit Class
Integer
Algorithm
This function uses the following algorithm:
1. Starting at the peak load index, search the curve backwards until the load drops by the tolerance amount
(tolerance is a percentage of peak load).
2. Using the zero slope segment length argument, search the curve backwards until the slope of the
segment becomes less than zero.
3. Find the minimum load point of this segment, referred to as the zero slope index.
4. Starting at the zero slope index, use the maxSlopeSegLen argument to search up the curve for the
segment with the highest slope value.
5. Draw a line for this segment and draw a horizontal line through the zero slope index.
6. Where these two lines intersect, calculate the value of the extension channel.
7. The YPE End index is the data point whose extension value is closest to this value.
244 | MTS TestSuite
Working with Variables