You are hereCYCLES 2.0: Fatique Reliability Models and Results for Wave and Wind Applications

CYCLES 2.0: Fatique Reliability Models and Results for Wave and Wind Applications


Report No. : 
RMS-27
Authors: 
A.K. Jha
Authors: 
S.R. Winterstein
Published: 
June 1997
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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 properti es). 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 g-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.