engleski

A sophisticated beam model for hydroelastic analysis of ultra large container ships

A numerical procedure for hydroelastic analysis of Ultra Large Container Ships (ULCS) which utilizes sophisticated beam model coupled with 3D BEM hydrodynamic model, has been summarized. Beside general description of the methodology for ship hydroelastic analysis and constitutive parts of the hydroelastic mathematical model, special attention is paid to several improvements of the beam structural model. The first one is related to derivation of finite element for coupled beam horizontal and torsional vibrations, with influence of shear on both bending and torsion. The second improvement includes contribution of transverse bulkheads to the hull torsional stiffness, based on theory of thinwalled girders and orthotropic plate theory, while the third one is related to an appropriate incorporating of the relatively short closed engine room segment into the beam model. The significance of theoretical considerations is confirmed within two numerical examples. The first example includes complete hydroelastic analysis of a 7800 TEU container ship, and in that particular case 1D FEM model is checked by correlation analysis with the vibration response of the fine 3D FEM model. The procedure related to the determination of the engine room effective stiffness is verified within the second numerical example, by 3D FEM analysis of ship-like pontoon.

Container ships, Hydroelasticity, Mathematical model, Restoring stiffness, Beam model

nije evidentirano