Vibration Control for Ship's Deck House using Vibration Intensity Analysis Method

摘要

Ship vibration analysis using finite element model has been conventionally carried out based on the mode superposition method. However, the structural modification based on the modal approach typically tends to be massive because the countermeasures to avoid a resonance are derived from the mode shape which vibrates globally. Also it is difficult to exactly consider the effect of damping elements in this method. On the other hand, vibration intensity analysis with the direct method visualizes the transmission and dissipation of vibration energy over the structure. In this paper, the vibration intensity analysis code was developed and then it was applied to a ship vibration problem. Through the application, the top-bracing and its supporting structure were identified as the main path of the vibration energy from the main engine. By the local modification of the top bracing and its supporting structure, the vibration intensity transmitted to the hull structure was controlled and thus the vibration at the deck house was reduced without notable variation of a natural frequency. Therefore, it was concluded that the vibration intensity analysis can be utilized as an effective approach to a ship vibration problem.