Fatigue Reliability for Offshore Structures

Abstract

The results of a four‐year project, sponsored by the American Petroleum Institute, to investigate the fatigue design process in the welded joints of steel offshore structures are summarized. Fatigue damage expressions were formulated. A simple analytical expression for damage based on the rainflow method of cycle counting in a wide band process was constructed. Because fatigue design factors have significant uncertainty, a reliability approach, using the lognormal format, was developed. The performance of Miner's rule was characterized statistically, as was modeling error associated with the process of computing fatigue stresses in a joint from oceanographic data. Procedures of S‐N data analysis were developed, and characteristic