Generally, there are many kinds of pumps used on a ship, which play an obbligato role to assist the ship’s running. However, due to the pump’s own motor, it becomes a main vibration resource that may cause serious problems in local. If the above situation happened, it may cause local resonance even structural damage. Also, the bigger the pump’s size is, the more serious the vibration is. Therefore, it is very important for researchers to estimate the vibrations situation of pumps accurately and avoid or reduce the probability of resonance. Based on a real marine pump-HHG8065, this paper did a vibration analysis by FEM (Finite Element Method) and compared the results with actual test. Finally, it gave a discussion on the estimation of pump and provided an improvement way to the vibration level.

A Korean-designed cruiser class sailing yacht, based on the form of traditional yachts, has been developed. In this paper, structural design procedures for the yacht are studied. The scantling of structural members and loads is carried out based on the guidelines suggested by Australian Standard 4132-1993, the American Bureau of Shipping (ABS) and the International Organization for Standardization (ISO). Patran/Nastran finite element analysis is performed on models of the trial sailing boat, and from these results, the structural strength of the ship’s hull is verified.

In vibration analysis of ships, the principle aim is to determine the natural frequencies and excitation frequencies, and use this information to avoid resonances and vibration damage. The simplest method is to prevent resonance conditions, which is effective as long as the natural frequencies and excitation frequencies can be regarded as independent from environmental conditions. For ships that use electric propulsion systems, the sources of vibration are reduced compared with those caused by a diesel engine or other combustion-based propulsion systems. However, the frequency spectrum of these vibrations may be different; therefore, to understand the characteristics of the electric propulsion, we also should investigate how the ship responds to these vibrations. We focused on a 1,000-ton deadweight (DWT) ocean-research vessel using an electric propulsion system and analyzed the response to vibration.