Integrated design method of marine C/GFRP hat-stiffened panels towards ultimate strength optimisation

Glass fibre-reinforced polymer (GFRP) hat-stiffened panels have been widely used in high-speed vessels. Using carbon fibre-reinforced polymer (CFRP) as hybrid composites can improve structural stiffness and strength by adopting reasonable material design methods. To show the advantages of the designability of composite materials, the integrated design of materials and structures has to be adopted. This paper establishes the multiscale analysis framework to assess the ultimate strength of marine carbon/glass fibre-reinforced hybrid composite hatstiffened panels with diverse composite designability. The equivalent material properties at the meso-scale obtained by a multiscale method define the macro-scale ultimate strength in finite element analyses. The investigation is focused on integrating material and structural design variables to optimise the ultimate strength of marine hat-stiffened panels. The response surface method is used to establish a surrogate model of the ultimate strength of marine hat-stiffened panels, and the multi-objective optimisation design is performed using Nondominated Sorted Genetic Algorithm - II (NSGA-II) with structural mass and ultimate load as optimisation objective functions. The analysis procedure provides the integrated design method of materials and structures to achieve the optimal design of composite stiffened structures.