An Investigation into the Application of the Modal Analysis to the Calculation o Transverse Vibration Responses of Ship Hulls

선체횡진동응답(船體橫振動應答)의 Model Analysis에 관한 고찰(考察)

The degree of deviation from the orthogonality relations of the actual ship's natural modes and its effects on the vibration responses are numerically investigated. The results show that, for the practical application of the modal analysis, it is not an essential requirement in utilization of the expansion theorem to assume the added mass being constant regardless of the mode shapes, or to take the dry hull's natural modes. That is, it is more reasonable to take the actual ships natural modes as the set of the normal modes and to get the solution of the normal coordinates equation by neglecting both the inertia coupling and the stiffeness coupling.