Thickness optimization of insulating glass unit in cruise ships

Paper in proceeding, 2022

Modern cruise ships employ more and more windows and glass structures, especially on the top decks. However, lightweight solutions are desirable as the cruise ships are weight and stability sensitive vessels. The design of the windows according to the classification rules is common for all type of passenger vessels and is based on linear plate theory for monolithic glass panes. However, the windows separating the indoor and the outdoor spaces are insulating glass unit-type (IGU) windows that consist of at least two glass panes separated by a hermetically sealed cavity. These IGUs exhibit two effects that the rules do not currently consider: 1) geometric nonlinearity of the glass panes and 2) load sharing between them. The authors recently included these effects in a nonlinear Finite Element analysis and showed their beneficial influence on the generated stress state of a rectangular IGU under static uniform pressure. There, only maximum principal stress design constraint was considered. However, there are other design constraints (e.g., deflection limit) that arise for fulfilling the IGUs intended function. Therefore, the nonlinear FE model and the design constraints are implemented in a Particle Swarm Optimization (PSO) routine to calculate the optimized thicknesses of the glass panes for different sized IGUs. Thus, this study aims to present how the different designs constraints affect the IGUs response and what are their implications on the reflected classification rules. The results indicate that the thickness determination is sensitive to the chosen constraints. Choosing the constraints is not a trivial task and requires further experimental work.