Effect of large openings without and with windows on the shear stiffness of side walls in passenger ships

Abstract

The side walls of passenger ships, ro/ro ferries and mega yachts are today characterised by large window openings which affect the structural behaviour. The main effect is the decrease in shear stiffness within the plane. This well-known effect is important to be considered in structural analyses, such as longitudinal strength analyses where the effectiveness of the upper decks is reduced. However, the vibration behaviour of the hull girder is also affected. The paper reviews the state of the art with respect to consider this effect in finite element modelling. Furthermore, an analytical procedure for the derivation of the shear stiffness based on beam theory is presented. As clamped and bonded glass panes contribute to the stiffness particularly in the case of large opening ratios, the modelling of the elastic connection between wall and glass pane is also considered. In addition to hints for finite element modelling, which requires a relatively fine mesh of the connection, also the analytical procedure is extended to consider this effect by using the differential equation for a beam on elastic foundation. Finally, the transfer of the derived shear stiffness into a global finite element model of the ship is outlined, illustrated by a numerical example.

Keywords:

• passenger ship
• window opening
• shear stiffness
• bonded window
• clamped window
• FEM
• beam theory

Acknowledgements

The investigations were performed within the project ‘Structural Behavior of Large Windows aboard Ships’ which was funded with public means within the programme ‘Industrial Cooperative Research’ by the German Federal Ministry of Economics and Technology via the AiF and was coordinated by the Center of Maritime Technologies (CMT) in Hamburg.