Recent development in the fast corrosion fatigue analysis of offshore structures subject to random wave loading

• Published in: International journal of fatigue Vol. 12; no. 6; pp. 458 - 468
• Main Author: Kam, J.C.P
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1990; Elsevier Science
• Subjects: Applied sciences; corrosion crack growth; Exact sciences and technology; fast fatigue analysis; Fatigue; Marine; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; offshore structures; wave loading; fast fatigue analysis; wave loading; corrosion crack growth; offshore structures; Stress distribution; Random load; Offshore drilling platform; Corrosion fatigue; Modeling; Crack propagation; Weld; Power spectrum
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/0142-1123(90)90217-3

In many areas of engineering, such as the offshore industry, welded steel joints are widely used as standard structural components. These joints are usually subject to long-term random wave loading and are therefore susceptible to fatigue damage. In many cases, the complex service loading is described by stress (or strain) power spectra, each representing a stationary sea state. These power spectra are obtained from hydrodynamic analysis or in situ monitoring. These will then be used in design calculations, feasibility studies or in-service assessment of fatigue damage on the structures. Usually, the power spectra will have to be realized into real-time histories and then counted before fatigue analysis can be carried out. On many occasions where a large number of design options or joints need to be analysed, this process becomes very time consuming and expensive. The situation is further complicated by the calculations involving corrosion fatigue for joints in sea water. The paper will start with a brief presentation of the fatigue analysis procedures for offshore welded joints and several existing models that were derived to bypass the laborious load history analysis mentioned above. More effort, however, will be concentrated on presenting the development of a new model. This model not only provides a more consistent and accurate prediction, but has also been adopted successfully for corrosion fatigue analysis.