Manufacturing of composite sandwich panel, and comparison of the panels manufactured according to failure criteria

In this study, composite panels with different core structures were investigated to increase the bending and compression stiffness of the panels. Three type of core structures were examined. These were pyramid, conical, and supported-conical. These panels were designed with inspiration from the egg box. Composite panels were produced using vacuum infusion method. Glass fiber fabric and epoxy resin were used to the manufacture cores and the face sheets, and epoxy-based adhesive was used to adhere the core and the facesheets. The bending resistance of the composite panels with different cores was very close to each other, but the bending resistance of the pyramidal core panel was higher than the others. In the compression test, the compressive strength and rigidity of the composite panel with supported conical core structure was about twice that of the other panels. The three-point bend test was modeled using the finite element method. Damage zones were determined using the Tsaih damage criterion in the model and compared with the test results. When the results were examined, the model found the damage areas close enough.