Application of Modal Analysis for the Vibrational Comfort Investigation on Board Ships: a Case Study

• Published in: Journal of marine science and application Vol. 23; no. 4; pp. 812 - 822
• Main Authors: Rognoni, Giovanni, Mažeika, Pranas, D’Amore, Giada Kyaw Oo, Brocco, Emanuele, Mickevičienė, Rima, Žapnickas, Tomas, Iamshchikov, Evgenii, Djačkov, Vasilij, Biot, Marco
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2024; Springer Nature B.V; Department of Engineering and Architecture,University of Trieste,Via Alfonso Valerio 7/4,Trieste 34127,Italy%Faculty of Marine Technology and Natural Sciences,Klaip(e)da University,Bijunu str.17 Klaip(e)da,LT,91225,Lithuania%CS.N.I:Scarl,Corso Perrone 27/R,Genova 16152,Italy
• Subjects: Catamarans; Comfort; Crew; Design; Electrical Machines and Networks; Engineering; Geotechnical Engineering & Applied Earth Sciences; Machinery and Machine Elements; Modal analysis; Navigation; Noise generation; Offshore Engineering; Power Electronics; Research Article; Research vessels; Ships; Vibration; Vibration analysis; Vibration measurement; Catamaran; Modal mass fraction; Suspended floor; Modal shape
• DOI: 10.1007/s11804-024-00502-6
• ISSN: 1671-9433

The design of a ship is a process facilitated by different parallel departments. Specialists from various disciplines jointly work on a project, eventually covering the entire process. Though simultaneously, these disciplines are often subject to a hierarchy, either clearly defined or dictated by necessity. Within these branches, despite a growing interest in enhancing the comfort on board ships, noise and vibration design is among the most sacrificed. Compared to hydrodynamic or structural modifications, efforts devoted to improving vibrational comfort are generally slightly impactful and costly. Consequently, these improvements are often relegated to the final stages of the design procedure. The underestimation of noise and vibrational comfort design can generate serious, unexpected issues emerging only in the advanced phases of the ship’s life, and post-construction interventions are often needed. This case is exemplified in the current study, where the crew of the research vessel Mintis, a catamaran-type hull, reported discomfort in the navigation wheelhouse. A measurement campaign was set up to assess the complaints of the operating personnel regarding the high vibrational levels. Subsequent to the measurements, a numerical simulation, specifically comprising a modal analysis, was conducted to investigate the nature of the disturbance and distinguish the underlying mechanism at its origin. This paper meticulously presents and discusses the strategy undertaken to analyze and solve the vibrational problem encountered on board, with particular attention to the criteria and the modeling considerations adopted.