MTS Fracture Template - Manual (Page 40)

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.
Analyze the Test Runs
Each test that you create from an MTS template contains a default analysis definition that can be used to
analyze the test run in either the Fatigue Analyzer or Fracture Analyzer application.
To analyze the test runs, use one of the following methods to open the test in one of the Analyzer
applications:
40 | MTS TestSuite
Fatigue Crack Growth (FCG) Template