On the lightweight design of laminated insulating glass units in cruise ships

Modern cruise ships employ many large windows to enable passengers to enjoy the marine environment. Most windows are insulating glass units (IGUs) consisting of laminated glass and a hermetically sealed cavity. These laminated IGUs exhibit three physical effects under bending: (1) geometric nonlinearity of the glass panes, (2) shear transfer in the laminated glass, and (3) load sharing due to the hermetically sealed cavity. The Authors have previously studied the (1) and (3) effects on the window mechanical behaviour and glass pane thickness determination. Hence, this paper investigates through optimisation how all these effects together lighten the IGUs, and how the shear transfer affects the IGU mechanical behaviour with the optimised thicknesses. All three combined effects have positive effects on the IGU weight. These results are more pronounced for large and thin IGUs subjected to high design loads. For example, the choice of interlayer material is less important (for optimum weight) for small windows subjected to a low design load. Since all the effects are important, using the finite element method is recommended to achieve a lightweight window design.