Object-oriented fatigue reliability analysis for the offshore steel jacket

In recent years, great progress has been made in fatigue reliability analysis for offshore steel jackets and many methods have been proposed. The existing analysis programs, however, are established on the basis of the structural mathematical model that is difficult to be extended. Therefore the new methods are difficult to add into the existing programs. In this paper, the innovative object-oriented (O-O) technique is introduced into the fatigue reliability analysis so that the maintenance ability of the reliability analysis system is greatly improved. With the use of O-O technique, program for the fatigue reliability analysis for offshore structures (FRAOS) has been developed. Both functions and components, such as structural modeling, wave loading, failure path etc. involved in the analysis are classified as independent objects. The corresponding class hierarchy is established and the analysis process is encapsulated within classes. Based on the established class structures, a generic fatigue reliability system for the offshore steel jacket is developed with Visual C++. The analysis results indicate that the computing process is more efficient and data structure is easier to manage and maintain with the use of O-O technique. Finally, a numerical example is given to demonstrate the feasibility of the proposed methods.