MTS Fracture Analyzer - Manual (Page 81)

StressA
StressA(StressMax, StressMin)
The StressA function returns the value: ((StressMax - StressMin)/(StressMax + StressMin))
StressR
StressR(StressMax, StressMin)
The StressR function returns the value: StressMin/StressMax
7.5.8.0 Fatigue Life Calculation Function
Fatigue Life
FatigueLife(YAxis, XAxis, startIndex, endIndex, percentageDrop)
The FatigueLife function returns the index of the point where the material under test fails. The failure point is
after endIndex where the Y-Axis value falls below (percentageDrop) the Least Squares Fit line of X-Axis and
Y-Axis data between startIndex and endIndex. This function provides the drop line for the Failure Cycle chart.
7.6.0 Data Acquisition Editor
The Data Acquisition Editor allows you to map signal data into variables that can be used to perform calculations
on signal data, perform logical condition checks for If-Else and While statements, and to log current signal
values. To access the Data Acquisition Editor, click Definition menu > Data Acquisition Editor.
In the Fatigue and Analyzer applications, you can map a variable to signal data and recalculate the data for
those cycles that are selected or defined in the properties for the Data Acquisition activity. The original test
data is not changed or lost.
MTS TestSuite™ Fracture Analyzer User Guide 81
7.0 Variable Analysis