Vibration Analysis of Motor Yacht

The comfort on board large motor yachts has become the object of specific attention by most important Classification Societies that issued new rules and regulations for the evaluation of noise and vibration maximum levels. These rules, usually named as "Comfort Class Rules", contain the general criteria for noise and vibration measurements in various yacht areas, and maximum limit values that such measurements should comply with them. In order to improve the comfort level onboard superyachts the University of Genova, in cooperation with one of the most important Italian shipyards, decided to start a comprehensive investigation on the dynamic behaviour of superyacht structures. The first phase of this activity has been represented by a complete review of existing comfort rules of most important Classification Society, a synthesis of which is presented in this work. In the second phase a detailed FEM analysis of a 60 meters superyacht have been carried out in order to investigate the natural frequencies of the main steel deck and of the superstructure light alloy decks. The numerical results have been compared with a first series of experimental data gathered during the vessel construction