Interaction between web-core sandwich deck and hull girder of passenger ship Jani Romanoff " Hendrik Naar 2 and Petri Varsta 1 1 Department ofApplied Mechanics/Marine Technology, Aalto-university Espoo, Finland E-mail: jani.romanoff@aalto.fi 2 Department of Mechanics, Tallinn University of Technology, Tallinn, Estonia Abstract Structural response of modern large passenger vessels is fairly complicated due to discontinuities created by open spaces, but also due to balcony openings. These two facts result in non-linear strain distribution along the depth of the hull girder. During recent years steel sandwich panels have been developed to decrease the structural weight, centre of gravity of the ship and also to ease the production of the ships through modularity. In order to make decks, the sandwich panels need to be joined. In order to implement these panels to load carrying deck structures ofthe modern passenger ship their influence on the structural response ofthe hull girder needs to be investigated. Therefore, the present investigates the interaction between hull girder ofpassenger ship and steel sandwich decks. Sandwich decks with both symmetrical and production friendly non-symmetricaljoints are considered and compared to the traditional decks made from stiffened plates. Both deflection and normal stresses are considered as the response. Keywords Passen ger ship; steel sandwich deck; response; joint Nomenclature A Extensional stiffness matrix S Web frame spacing B Coupling stitfness matrix Stiften er spacing D Bending stiffness matrix Plate thickness d Distance between the neutral axes of the face plates u Displacement in x-direction D Q Shear stiffness matrix v Displacement in y-direction E Young's modulus w Displacement in z-direction G Shear modulus E Normal strain h Height v Poisson's ratio N Normal force 8 Rotation M Bending moment (J Normal stress k Stiffness parameter T Shear stress Q Shear force K Curvature q Pressure load 1 Introduction Structural response of modern large passenger vessels is fairly complicated due to discontinuities created by open spaces in general arrangements ofthe ship; such spaces are atriums, theatres, main restaurants etc. On the other hand side structures ofthe superstructure have fairly low shear stiffness due to balcony openings. These two facts result in non-linear strain distribution along the depth ofthe hull girder; see for example Bleich, (1953), Fransman (1988) Naar et al. (2004). In addition shear lag effect may become important (Naar et al. 2004). Submitted 10 MS&OT on Mar 25 2011. Aceepled on Oel 13 2011. Editor: Marcelo A. S. Neves Val. 6 No. 1 pp. 39-45 June 2011 Marine Systems & Ocean Technology 39