MTS Fatigue Analyzer - Manual (Page 47)

Description Item
Shows a panel to set one variable value. The selected marker value appears
in the New Failure Cycle Chart panel. The Value box is unavailable and you Add Marker Value
cannot change the value. The Units box has a drop-down button that shows
a list of unit options. The content of the list is context-sensitive and depends
on the marker selection. The marker’s value and units appear, but the marker
is not added to the chart.
When you add a marker value to the chart, the Remove Marker Value button
becomes active. It remains active until you select a button on the Markers
toolbar or you click in a box in the Markers panel. Remove Marker Value
5.3.5.0 Drop-Line Markers
On the Failure Cycle chart, two markers, Drop-Line Start and Drop-Line End, are typically defined relative to
the stable cycle and crack initiation cycle. Drop-Line Start represents the stable cycle. Drop-Line End represents
the crack initiation cycle. The drop line markers provide a way of moving markers on the chart curve without
overriding the stable cycle or crack initiation cycle values.
Drop-line marker buttons are best illustrated using a simple example.
1. Click the Add Marker Line button to add a marker line.
2. Click Drop Fit Start for the first marker and click Drop Fit End for the second marker.
The Remove Marker Line button becomes active.
3. Click the Add Marker Point button to add a marker point, and select Failure Cycle Number.
The Remove Marker Point button becomes active.
4. Click the Move box of the Drop Fit End marker.
The Remove Marker Line button becomes active.
5.3.6.0 Cycle Marker Chart
The Cycle Marker chart plots the loading modulus and the unloading modulus. Additionally, this chart can be
used as a Hysteresis chart with markers. The variable and index selection interface is the same as for the
Hysteresis chart. Marker points, lines, and values can be added in the same way as with the History Marker
chart. However, the Cycle Marker chart uses indices from the array index, rather than cycles. The array index
depends on how the timed data was sampled and is not shown on the chart. To create a new Cycle Marker
chart, click the New Cycle Marker Chart button.
The typical calculation for the loading modulus or the unloading modulus is:
Loading Modulus(Stress Array, Strain Array, IndexLow, IndexHigh)
The calculation for IndexLow and IndexHigh is -1. This value causes the function to determine the index when
calculating the modulus. If you move a marker on the chart, the calculation is performed using the array value
at the index designated by the marker. The modulus value is calculated for only the cycle currently shown
on the History Marker chart.
MTS TestSuite™ Fatigue Analyzer User Guide 47
5.0 Customizing the Main Window