Professor and director, Center for Marine Materials, Boca Raton, FL
Pages: 16 Published: Jan 1990
Fatigue is a potentially important failure mode for offshore structures. Development of realistic data (high-cycle regime of the S-N curve or near-threshold region of the crack growth rate-stress intensity range curve) is made difficult by the fact that load excursions are mostly of low amplitude (high-cycle fatigue) with frequency in the range of 0.05 to 0.5 Hz; and so one or more years of testing may be required to establish a single data point (S-N approach) or da/dN-ΔK curve. In the present paper experimental alternatives for developing both fatigue life and crack growth rate data for offshore applications are presented, with particular emphasis upon test parameters and variables of importance. Special emphasis is placed upon techniques for multiple specimen testing. In addition, a novel approach for characterizing near-threshold fatigue crack growth rates within realistic test periods is proposed and discussed.
corrosion fatigue, fatigue testing, crack initiation, crack propagation, steel, welded steel, variable amplitude, polarization
Paper ID: STP26101S