Frequency Domain Analysis for Float-over Barge Subjected to Random Waves

Floatover barges are used for the installation of topsides
onto jacket platforms recently. In this study, a frequency domain
analysis was performed for a float-over barge subjected to
random waves. The excitation forces acting on the floating barge
were derived by Froude-Krylov approach. In this paper, seven
different sea states were specified for the analysis and the results
are presented in terms of Response Amplitude Operators
(RAOs). Three motion modes were analyzed namely surge,
heave and pitch. The results are presented and conclusions
arrived at. The resulting RAOs decrease with an increase in
draft while longer wave periods are associated with larger surge,
heave and pitch responses. The findings provide guidance for the
conceptual design and development of such structures.
Keywords - float-over barge; frequency domain analysis; random
waves; dynamic analysis; Froude-Krylov approach.