engleski

Influence of Large Shell Openings Geometry in Ship Superstructure on Stress Concentration Reduction

The ship structure of modern multi-deck ships (e.g., cruise, passenger and RoPax ships, livestock carriers, RoRo ships etc.) is characterized by large openings in a superstructure shell plating. Such openings have a great influence on primary stress distribution over the ship overall depth and longitudinal ship strength. Due to a combination of shear-bending load, high stresses are concentrated around corners of large openings, which could be decreased by choosing the proper geometry of the opening. Parametric study is carried out to investigate the influence of geometry around the corners of the openings on stress concentration reduction. Thirty six (36) partial 2D models of superstructure side shell plating has been generated using a finite element method (FEM) and the structural response of the models has been analysed. The results are presented in dimensionless form by introducing a stress reduction coefficient. The stress reduction coefficient has been defined as the ratio of the stress of a geometrically improved corner (with a certain radius) and a corner without radius (right angle). Response surface of stress reduction coefficient with respect to a size of the corner radius and size of openings has been generated. The accuracy of the proposed response surface results was finally tested on a global full ship 3D FE model of large livestock carrier with a realistic set of the design load cases.

: Large side superstructure openings ; Multideck ships ; Stress concentrations ; FEM

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