The sandwich construction combined with composite materials for fuselage structures could be the new concept of future aircraft structures which provide the benefit of reduced weight and assembly costs.
In this paper, we performed a static structural analysis of fuselage skin structures with three different structural concepts, which were composite sandwich fuselage skin structure with the different core thickness, the fuselage skin assembly division method, and ring frame shapes. The optimal design for the fuselage skin structure was also performed based on these results. Results of structural analysis and optimization for fuselage skin structure with three structural concepts showed that the weight reduction of composite sandwich fuselage skin structure were approximately 21% and 50% compared to composite laminates and aluminum fuselage skin structures, respectively. Results of structural analysis and optimization for the composite sandwich fuselage skin structure with different core thickness showed that the lightest weight of sandwich fuselage structures were achieved in the range of 5-10mm core thickness.
Structural analysis and optimization of the composite sandwich fuselage skin structure by assembly division method were analyzed separately for the horizontal and vertical assembly division method. The vertical assembly division method showed superior performance over the horizontal assembly division method in regarding to the ring frame fastening and structural safety. Therefore, the vertical assembly division method was selected for further analysis, The vertical assembly division fuselage with three different c-shaped, hat-shaped, hexa-shaped ring frames were analyzed. As a result, the hexa-shaped ring frame were shown excellent structural safety and weight reducing effects compared to the other shaped ring frame.
Finally, a conceptual structural design of a composite sandwich fuselage for civil aircraft was discussed to show the feasibility of the concept. It was shown that the required facing and core thickness were within an applicable design.
Further studies such as failure behavior of various composite sandwich structures and fuselage assembly division method are needed to provide a step forward in integrated design and engineering of composite sandwich fuselage.