MTS Multipurpose Simulated - Manual (Page 55)

Validity Results Table
The Validity Results table includes the Display Name, Value, Modified Indicator, Original Value, and Calculation.
The Display Name includes the validity criteria. The Value and Original Value columns contain indicators that
are Yes or No values. The validity of the test results can change because of changes in test values.
da/dN, Delta K by Cycles Table
The da/dN, Delta K by Cycles Table lists all data points collected in the Fatigue Crack Growth da/dN array.
If no valid points are collected, an error may occur. If data is reduced using the Secant fit method, two valid
points are required or an error may occur. If data is reduced using the Polynomial fit method, an error may
occur if the number of valid points is less than the two times the polynomial fit number plus 1. The number
of valid points is used to calculate the Apparent Delta-K Threshold. Invalid data points are not used in
calculations.
The Apparent Threshold calculation can fail:
• The da/DN-Delta K data is not available.
• The Least Square Fit limits are outside the range of the da/dN-Delta K data points.
• The Least Square Fit limits range is a number of valid da/dN-Delta K data points less than two times the
polynomial fit number plus 1.
Crack Length, Min/Max K, Load by Cycles Table
The Crack Length, Min/Max K, Load by Cycles table provides values for the cycles in the FCG Cycle Array
column. Additional default columns are:
• FCG Crack Size Array
• FCG K Maximum
• FCG K Minimum
• FCG P Max Array
• FCG P Min Array
• FCG COD Voltage Active Array
• FCG Crack Voltage Reference Array
Charts
The charts provide visual indicators of the crack growth rate and the forces that affect the rate.
• The da/dN vs. Delta K chart characterizes the specimen material’s resistance to stable crack extension
under cyclic loading.
• The Load vs. Cycle chart indicates the load range between the minimum and maximum values during the
last or other specified cycle.
• The Crack Opening Displacement vs. Cycle chart indicates the minimum and maximum crack opening
displacement during the last or other specified cycle.
• The Crack Size vs. Cycles chart indicates the crack growth during a number of cycles.
• The K vs. Cycles chart indicates the stress intensity factor, K, between its minimum and maximum amount
during a number of cycles.
• The Delta K vs. Array chart indicates the FCG Delta K Applied Array versus the FCG Crack Size Array.
MTS TestSuite 55
5.0 Running Simulation Tests