V‐shaped truss‐like cores for improving mechanical properties of woven lattice sandwich composites

Abstract Woven lattice sandwich composites with 1‐shaped truss‐like cores have the disadvantage of weak core shear performance. In this paper, double‐layered woven lattice sandwich (DWLS) composite panels with V‐shaped truss‐like cores were designed and manufactured to solve the weak core shear performance of 1‐shaped truss‐like cores. Flatwise compressive and three‐point bending experiments were performed on these DWLS panels. Results indicate that V‐shaped truss‐like cores improve the flatwise compressive strength and stiffness, and the core shear stiffness and strength of panels compared to 1‐shaped truss‐like cores. The V‐shaped core piles fracture at the end, while the 1‐shaped core piles fracture at the middle. The improved core shear stiffness makes the V‐shaped panel exhibit more excellent mechanical performance. In three‐point bending experiments, the obvious inflection feature and its induced large deformation appear in the supported end but are suppressed as the span increases. The theoretical approach was used to calculate core shear stiffness, and the analytical results are in good agreement with the experimental patterns. Highlights Woven lattice sandwich composites with V‐shaped truss‐like cores were proposed. Double‐layered woven lattice sandwich (DWLS) composites with various truss‐like cores were manufactured. Mechanical properties of DWLS composites with various truss‐like cores were revealed.