DESIGN STUDY ON LONGITUDINAL STRENGTH OF A 164-CABIN CRUISE SHIP IN WAVES

To examine thePvalidity of inclusion of very thin deck plates of superstructure and deckhouse to longitudinal strength, a direct analysis of the longitudinal strength of a 164-cabin cruise ship in waves was performed by the combination of a strip method calculation and a series of full 3D-FE-analyses. Reduction of effective width of the plates by compressive stress which was estimated by Carlsen's formula was taken into account in the 3D-FE-model, and hydrodynamic pressure and inertia forces obtained by the strip method calculation were used directly as external loads. A series of non-linear FE-analyses of a thin rectangular plate was also performed to investigate its characteristics under axial compression, and the applicability of Carlsen's formula to very thin plates has been ascertained. It was found that although the very thin deck plates of superstructure and deckhouse contribute to the longitudinal strength quite effectively, due to the reduction of effective width width of the plates, hull-girder section modules is reduced by almost 45% under sagging bending moment. Evaluating the ultimate strength of deck longitudinals can be one of the methods to assess the longitudinal strength.