Cycles 2.0: Fatigue Reliability Models and Results for Wave and Wind Applications

摘要

CYCLES is a computer program that computes the fatigue reliability of mechanical components. It includes a rather flexible model of uncertainty, both in distribution parameters of randomly varying quantities (e.g., load environment parameters such as wave height, wind speed, etc.) and in uncertain material properties (e.g., S-N fatigue properties). The formulation is intended to be of general applicability across a range of fatigue problems. Applications are shown here to offshore structures and wind turbines, both of which may experience fatigue problems. These models are efficiently analyzed through FORM/ SORM techniques (first-and second-order reliability methods). A simple, analytical 9-function (limit state) is established, which may be directly incorporated into standard FORM/SORM software packages. We describe here one such code, which includes a 24-variable formulation, its capabilities, input parameters, and output. Fatigue reliability results are shown from this code for both wave and wind applications, including failure probability variation across a range of target fatigue lives.