Evaluation of Seasonal Effects and degrees of freedom on Dynamic Response and Impact Forces on Leg Mating Unit in Persian Gulf

This paper evaluates the dynamic response and forces acting on the leg mating unit for the weather conditions in the Persian Gulf in the four seasons of the year. A six-degree-of-freedom model dedicated to the Floatover installation has been developed to provide a dynamic response and the forces acting on the leg mating unit, which acts as a shock absorber for the impacts caused by movements of the vessel. In addition to evaluating the dynamic response of the barge and deck in the frequency domain, the forces applied to the leg mating unit are obtained in the time domain. These forces have been obtained for 100% loading for different environmental conditions. The impact forces are assessed for a 2 minutes time history. In the hydrodynamic model, significant wave height, wave period, velocity, and wind direction were considered as input parameters. The effect of increasing degrees of freedom on the variations in Mooring forces was also considered. According to the results of the forces on the leg mating units, it is recommended that this installation be done in the summer due to the fewer changes in the forces, and to prevent overdesign conditions or possible failure, mooring forces be calculated in every six degrees.