ABSTRACT

The jacket structures are often employed in the range of shallow-moderate water depth. The bracing systems and jacket legs typically use the circular section in order to compromise the hydrodynamic resistance and high torsional rigidity However, under lateral impact, these tabular bracing members are susceptible to local denting due to ship collisions or through impact of falling objects and that can weaken overall performance of the entire platform. It is a great significance for forecasting dent depth of these members accurately. This paper investigates the use of adaptive meta-heuristics algorithm to provide an automatic detection of denting damage in an offshore structure. A model is developed combining with the percentage of the dent depth of damaged member diameter and is used to assess the performance of the method. It is demonstrated that the small changes in stiffness of individual damaged bracing members are detectable from measurements of global structural motion.