MTS Fatigue Template - Manual (Page 48)

displacement for failure detection. When the stability reference cycle is reached, the test compares the peak
displacements to this cycle to determine if the test should be terminated due to specimen failure.
Crack initiation determination
After a stable cycle is identified, each subsequent cycle is compared to the stable cycle. If the non-controlling
range (force range for a strain controlled test) deviates by the user-entered percentage, the application stores
the cycle number as the crack initiation cycle. Typical range drops are near 5%.
Peak-valley control failure
If the control value end levels are not met, the test stops.
Ramp to mean load
When the test is complete, the system changes to force control and ramps to mean load at a rate set by the
user.
6.3.9.0 Strain Test
In the LCFS test:
1. Click Strain Test.
The MTS TestSuite Custom Message window appears with the message: Validate test parameter on
runtime display. Click Run Test to start testing. Click Change Parameters to go back and change any
parameters.
2. Click Run Test to start the test. A message appears: Click the Run button to start the Strain test.
3. Click the Run button. The Run button changes color.
4. Click Change Parameters to view the main menu, where you can change parameters and run the test.
6.3.10.0 Reattach Extensometer
If the test stops and you want to resume it, you must reattach the extensometer. On the main menu, click
Reattach Extensometer.
A window appears that shows the End of Test Readings and the Mean Load Test Readings settings and
limits. You can click Verify Settings to see the strain and load readings again or Cancel to return to the main
menu.
6.3.11.0 Create a Fatigue Test Report
On the test main menu, click Report.
The application opens Excel. The Creating Report window shows you the progress as the application
creates a report with the test results.
You can make changes to the report and customize the output using the Reporter Add-In for Excel.
48 MTS TestSuite
6.0 ASTM Low-Cycle Fatigue (LCF) Elevated Temperature Template