Vibrations of superyacht structures: Comfort rules and predictive calculations

摘要

The comfort level on board modern superyachts has been recently the object of specific attention by most important Classification Societies which issued new rules and regulations for the evaluation of noise and vibration maximum levels. Such rules, usually named as "Comfort Class Rules", contain both the general criteria for noise and vibration measurement in various yacht areas, and maximum limit values which such measurements should fall into. Comfort Class Rules follows the ISO Standard 1984 formulation, recently removed by the ISO 2000 "Mechanical vibration—Guidelines for the measurement, reporting and evaluation of vibration with regard to habìtability on passenger and merchant ships”. In this work, performed in cooperation between Azimut?Benetti Shipyards and the Department of Naval Architecture of the University of Genova, a complete review of the existing rules is presented, together with a case study developed on a 60 meters superyacht, on which a detailed FEM investigation has been carried out in order to investigate the dynamic behaviour of hull and superstructures. The results of modal and transient analyses are compared with a first series of experimental data gathered during the vessel construction.