Characterization and modeling of bending properties of continuous fiber reinforced C/C-SiC sandwich structure

Due to their excellent stiffness-to-weight ratio, sandwich structures are considered as typical lightweight structure and have been widely used in aerospace and construction industries. Compared to traditional sandwich structures made of cardboard, aluminum and polymer material, sandwich structures based on ceramic matrix composites (CMCs) can achieve significantly higher service temperatures and longer lifetime. In this study, the sandwich structures based on continuous fiber reinforced cores and skin panels have been developed via Liquid Silicon Infiltration (LSI) and in-situ joining methods. For FE-simulation (Finite Element simulation), a realistic model was developed, and the mechanical performance of C/C-SiC sandwich structures under four-point-bending was analyzed. Bending and shear stiffness of the sandwich structures were determined by FE-simulation and analytical methods. The results obtained by modeling approaches were compared with experimental results and the comparison showed good correlation. The analytical and FE-simulation approaches have been further used to study the parameter effects and the influence of the different core structures on the bending properties respectively. The proposed different approaches are suitable to determine and simulate the mechanical properties of C/C-SiC sandwich structures and are applicable for further product development