MTS Series 793 Application - Manual (Page 471)

Model 793.14 Fatigue Monitoring Application
MTS MultiPurpose TestWare® Trend and Fatigue Monitoring Applications 471
About Best Case/Worst Case
The terms “worst case” and “best case” refer to the methods MPT uses to analyze
each histogram bin. Each histogram bin has an associated cycle count that
increments whenever a data value occurs within the bin boundaries. Therefore,
when analyzing the damage content of a histogram, the MPT analysis assumes a
maximum or minimum bin value for each cycle that is counted. The bin size
(resolution) affects the best case/worst case answers. The larger the bin size, the
larger the potential for errors in the damage calculations. In general, assuming
maximum values for a bin results in a maximum damage (worst case) scenario.
Likewise, assuming minimum values for a bin results in a minimum damage
(best case) scenario.
Worst case
“Worst case” assumes that the cycles in the bin have the largest range and tensile
mean (for strain life and generic stress life damage models) and that the cycles
“hang” from the bounding hysteresis loop in a way that yields the maximum
(tensile) mean stress (for strain life damage models only).
Best case “Best case” assumes that the cycles in the bin have the smallest range and tensile
mean (for strain life and generic stress life damage models) and that the cycles
“hang” from the bounding hysteresis loop in a way that yields the minimum
(tensile) mean stress (for strain life damage models only).
Limit Action For a data file: Displays the action settings.
For a procedure file: Displays editable action settings. To change a setting,
double-click it. A list appears with the following options:
None—Limit is disabled.
Warning—A warning message is issued and a message is written to the MPT
Specimen Log.
Stop—The process stops and a message is written in the MPT Specimen Log.
Trigger—The process triggers another process.
Status bar Displays the name, full scale and dimensions of the selected channel.
Limit Settings Window (part 2 of 2)
I TEM D ESCRIPTION