Abstract
The modal analysis method is very useful for the numerical calculation on elastic oscillation of a very large floating structure, while we have not discussed yet the applicability of modal analysis for the numerical calculation of sea shock response of a very large floating structure. Therefore, we introduce the direct calculation method which is a kind of the influence function method, and comparing both methods with each other.
The conclusions obtained by the present paper are that the calculation results of the modal analysis for elastic oscillation of a very large floating structure due to sea shock forces is not in good agreement with the direct calculation method which is more reliable. In addition, characteristics of sea shock response of a very large flexible floating structure in shallow water based on the direct calculation method are almost the same as the vibration of sea bottom and very close to those of a rigid structure.
