Prediction of Cumulative Fatigue Damage of Mooring Dolphins

Very Large Floating Structures, so-called Mega-Floats, are the kind of social infrastructures. They are generally expected to keep their integrity for a long period, for example, more than 100 years. So, it is necessary to develop Long-Term Integrity Prediction and Diagnosis System to diagnose the soundness of Mega-Floats. In the present study, we paid our attention to dolphin-fender type mooring devices that pontoon type VLFS are equipped with. As a part of Long-Term Integrity Prediction and Diagnosis System, we developed a long-term integrity prediction code (Cumulative Fatigue Damage Prediction Code) to predict damage of these dolphins. We made an at-sea experiment with pontoon type VLFS model of 201.5 [m] length, 100 [m] breadth, and 3 [m] depth (We call this “At-Sea Experiment for Verifying Functions of Mega-Float Information Data Center”). The model had two dolphin-fender type mooring devices and we applied Cumulative Fatigue Damage Prediction Code to these devices.