The unsymmetrical From-To cycle counting keeps more information about the loading cycles than Range-Mean counting does, because it also stores the "orientation" of each load cycle. This is important information if you want to reconstruct a time history from a Rainflow matrix.
The Rainflow counting of Simcenter Tecware (formerly called LMS Tecware) is a From-To cycle counting, and thus the default representation of the Rainflow matrices are also in From-To form.
However, Tecware also allows changing the representation to Range-Mean matrices. In fact, a Range-Mean histogram can always be derived from a From-To histogram, but not vice versa. This is because the From-To representation includes additional information (as mentioned above).
Example:
Look at the two load histories below:
![time_hist.png time_hist.png](media/0EM4O00000112ga)
They both have the same mean level and the same number of cycles, and the cycles' amplitudes are identical. The only distinctive property is the opposite polarity.
![from_to.png from_to.png](media/0EM4O00000112gb)
Looking at the Rainflow matrices of the two load histories, we get in the From-To representation:
![from_to_matrix.png from_to_matrix.png](media/0EM4O00000113FP)
The Rainflow matrix of "Load_up" shows hanging cycles, whereas the corresponding Rainflow matrix of "Load_down" shows standing cycles.
The denotation hanging and standing is motivated from the stress-strain-path. There, a hanging event is connected to the superior hysteresis branch at its upper reversal point, but a standing event is connected at its lower reversal point.
![sig_eps.png sig_eps.png](media/0EM4O00000113FQ)
When a load cycle is just represented by its range and mean, the distinction between hanging and standing is not possible. Thus, the Range-Mean representation for both of the signals looks like this:
![range_mean_matrix.png range_mean_matrix.png](media/0EM4O00000113FR)
Remarks:
The desired representation of a Rainflow matrix can be set in the "RainView layout" window, which is available via the menu Options -> Layout within the Rainflow matrix display.
![rain_view.png rain_view.png](media/0EM4O00000113FS)
Rainflow matrices can only be edited in the From-To representation.
Questions? Contact Siemens Support Center or post a reply.
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