Fatigue

Rainflow Counting Procedure

Rainflow counting is generally accepted as being the best cycle counting method up to date and has become the industrial de facto standard.

The idea behind the method is to detect the hysteresis loops in the load signal. We'll refer to the hysteresis loops as the closed cycles. Parts of the signal that do not correspond to the closed cycles are the so-called open cycles or residuals.

Different rainflow counting standards, such as ASTM, DIN and AFNOR, differ with respect to the treatment of the residuals. In order to be as general as possible the Fatigue Analysis Module supports both residual and non-residual mode.

Visualization

In order to graphically represent the results the fatigue analysis module uses the most common visualization techniques used in fatigue analysis:

• Range histograms - 2-D graph representing the range distribution of a load signal (range, number of cycles). A typical range histogram use-case would be to obtain the range histogram of a signal, rotate it over diagonal (swap the X-axis and Y-axis), overlay a corresponding S-N curve on top and check whether it stays well below the curve.
• From/to matrices - 3-D graph representing the cycle distribution of a load signal (from, to, number of cycles)
• Range/mean matrices - 3-D graph representing the cycle distribution of a load signal (cycle range, cycle mean, number of cycles)

Classes parameter specifies the number of classes the range is divided into. When Auto checkbox is ticked DEWESoft automatically calculates Min range and Max range from the input signal.

Formation gratuite en ligne

Vous pouvez apprendre plus sur l'analyse modale de DEWESoft en parcourant le PRO training Fatigue Analysis PRO training course.

Dewesoft PRO training est un cours gratuit en ligne pour les professionnels de la mesure. Apprendre à mesurer des signaux, à les traiter, et à utiliser les produits Dewesoft.