MTS Multipurpose Elite - Manual (Page 230)

The StrainA function returns the value:
((StrainMax - StrainMin)/(StrainMax + StrainMin))
StrainR
StrainR(StrainMax, StrainMin)
The StrainR function returns the value:
StrainMin/StrainMax
StressA
StressA(StressMax, StressMin)
StressR
StressR(StressMax, StressMin)
The StressR function returns the value:
StressMin/StressMax
Index Functions
This section contains reference information about index functions.
Understanding Index Functions
Index functions are used to find array index values. All array variables collected by a data acquisition
activity share the same index values. Once you create a variable that stores an index value, you can use
that variable in an Array Value function to return a value at that index. For example, to find the strain value
at peak load, you would use the following variable calculations:
PeakLoadStrainValue and Peak Calculations
Note:
The “Peak” variable stores the index value for peak load. The “PeakLoadStrainValue” variable uses
the ArrayValueAtIndex function to calculate and store the strain value at the peak-load index.
Determining Analysis Region
The “min load”, “max load”, and “% strain point arguments” are used to determine the bounding analysis
region for the algorithm. On a successful completion of this function, the index point will be contained
within the bounds of the analysis region. The analysis region is used to focus on important regions of data
and skip anomalous regions. If neither the starting or ending regions are located, all of the data in the
channels will be analyzed.
230 | MTS TestSuite
Working with Variables