1. Fatigue 1.1. Purpose Perform rainflow counting of load cycles and calculate fatigue damage. 1.2. Description The following method has been implemented: J.B. De Jonge: the monitoring of fatigue loads, National Aerospace Laboratory NLR, the Netherlands. ICAS Paper No. 70-31, 1970 1.3. Input Any equidistant signal (see Signal Types ). A SN-curve must be referenced in the editor for the fatigue function. A new SN-curve can be added by right-clicking the post processor task in the navigator and choose New > SN Curve. See also SN-Curve. 1.4. Output There are three output slots: Damage: Damage for each component for each sea state. Weighted damage: Damage for each component for each sea state, weighted with the probability of occurrence for each sea state. Accumulated damage: Accumulated damage for each component, that is, the sum of the weighted damage for each component. Fast Fourier Transform (FFT) Axial Stress