Sandwich composites are three-dimensional (3D) composite structures that offer higher stiffness with overall low density. However, they suffer from low strength; thus, not suited for load bearing applications. In this work, an attempt is made to develop a high strength lightweight sandwich composite suited for load-bearing applications. A sandwich composite based on 3D integrally woven fabric with thickness 3 mm as the core and strengthened with additional 2x2 twill woven carbon fabric face-sheets is reported. The samples were manufactured by wet hand lay co-lamination process using Araldite® LY 1564 epoxy as the matrix polymer and with fiber fraction of 50% by weight. The number of additional carbon face-sheets over the core was varied from two to eight in steps of two. The composite samples were experimented under three-point bending and edgewise compression tests to determine the flexural and compressive strengths in both warp and weft directions. The weft direction samples yielded higher flexural and compressive strengths due to the continuous arrangement of the core pile yarn. The samples with six carbon face-sheets tested along the weft direction offered the highest specific strengths of ~409 kN m/kg and 259 kN m/kg in bending and compression tests. Similarly, the flexural strength was ~340 MPa, and compressive strength was ~217 MPa. A detailed fractography study revealed no core crushing or compression failure of the core during bending tests.

三明治复合材料是三维（3D）复合结构，可提供较高的刚度和总体较低的密度。但是，它们的强度低。因此，不适合承重应用。在这项工作中，试图开发一种适用于承重应用的高强度轻质夹芯复合材料。报告了一种三明治复合材料，该复合材料基于3D整体机织织物，厚度为3 mm，并用其他2x2斜纹机织碳纤维织物面板加固。样品通过湿法手糊共层压工艺制造，使用LY 1564环氧作为基体聚合物，纤维分数为50％（重量）。核上额外的碳面板的数量以2为步长从2变到8。在三点弯曲和边缘压缩试验下对复合材料样品进行了试验，以确定经向和纬向的弯曲和压缩强度。由于芯绒纱线的连续排列，纬向样品产生较高的抗弯强度和抗压强度。在弯曲和压缩测试中，沿纬线方向测试的具有六个碳面板的样品提供的最高比强度约为409 kN m / kg和259 kN m / kg。同样，抗弯强度约为340 MPa，抗压强度约为217 MPa。一项详细的断层扫描研究表明，在弯曲测试过程中，没有发生芯破碎或芯压缩的故障。由于芯绒纱线的连续排列，纬向样品产生较高的抗弯强度和抗压强度。在弯曲和压缩测试中，沿纬线方向测试的具有六个碳面板的样品提供的最高比强度约为409 kN m / kg和259 kN m / kg。同样，抗弯强度约为340 MPa，抗压强度约为217 MPa。一项详细的断层扫描研究表明，在弯曲测试过程中，没有发生芯破碎或芯压缩的故障。由于芯绒纱线的连续排列，纬向样品产生较高的抗弯强度和抗压强度。在弯曲和压缩测试中，沿纬线方向测试的具有六个碳面板的样品提供的最高比强度约为409 kN m / kg和259 kN m / kg。同样，抗弯强度约为340 MPa，抗压强度约为217 MPa。一项详细的断层扫描研究表明，在弯曲测试过程中，没有发生芯破碎或芯压缩的故障。