On fatigue damage assessment in bimodal random processes

Rainflow fatigue damage in bimodal Gaussian processes is discussed. Some methods specifically developed for bimodal processes (e.g., single-moment, Jiao–Moan, Sakai–Okamura and Fu–Cebon method) are compared with the Tovo–Benasciutti method, a new approach valid for the broader class of wide-band processes. Further, an improvement of the Fu–Cebon method is also proposed. Numerically simulated bimodal random processes are used to compare the accuracies of all methods and to find the optimal range for their applicability. The single-moment, the modified Fu–Cebon and the Tovo–Benasciutti methods are seen as the most accurate over a wide combination of bimodal spectra.