Fluted-core sandwich composite structures are major load-bearing components used in launch vehicles. Herein, analytical models were proposed to investigate the failure mechanisms of fluted-core sandwich composite panels, including global buckling, local buckling, and material failure. Failure mode maps of fluted-core sandwich panels were constructed to analyze the intrinsic impact mechanism of geometric parameters on failure behavior. Integrated fluted-core sandwich composite panels were then fabricated by adopting the integrated forming process and co-cured method. Uniaxial compression tests and finite element simulation were also conducted to verify the analytical predictions with good consistency. The effects of the geometric variable on both load-bearing capacity and failure modes of the structures were explored. The results indicated the occurrence of global buckling at small distances between the top and bottom face sheets, resulting in undesired load-carrying capacities. The decrease in width of short span or increase in thickness of face sheets prevented such local-buckling behavior, resulting in material failure. The triangular-shaped core with zero short spans was identified as a better option for material failure as dominant failure mode for designing load-bearing sandwich panels. These findings look promising for lightweight and load-carrying applications, providing a reliable reference for the initial design of such sandwich structures.

槽芯夹层复合结构是运载火箭中使用的主要承重部件。在此，提出了分析模型来研究槽芯夹芯复合板的失效机制，包括整体屈曲、局部屈曲和材料失效。构建槽芯夹芯板失效模式图，分析几何参数对失效行为的内在影响机制。然后采用一体化成型工艺和共固化方法制造出集成槽芯夹芯复合板。还进行了单轴压缩试验和有限元模拟，以验证分析预测具有良好的一致性。探讨了几何变量对结构承载能力和破坏模式的影响。结果表明，在顶部和底部面板之间的小距离处会发生整体屈曲，从而导致不希望的承载能力。短跨宽度的减小或面板厚度的增加阻止了这种局部屈曲行为，从而导致材料失效。作为设计承重夹芯板的主要失效模式，具有零短跨度的三角形芯被确定为材料失效的更好选择。这些发现对于轻量化和承载应用很有前景，为这种夹层结构的初始设计提供了可靠的参考。短跨宽度的减小或面板厚度的增加阻止了这种局部屈曲行为，从而导致材料失效。作为设计承重夹芯板的主要失效模式，具有零短跨度的三角形芯被确定为材料失效的更好选择。这些发现对于轻量化和承载应用很有前景，为这种夹层结构的初始设计提供了可靠的参考。短跨宽度的减小或面板厚度的增加阻止了这种局部屈曲行为，从而导致材料失效。作为设计承重夹芯板的主要失效模式，具有零短跨度的三角形芯被确定为材料失效的更好选择。这些发现对于轻量化和承载应用很有前景，为这种夹层结构的初始设计提供了可靠的参考。