Influence of cell geometrical parameters on the mechanical properties of 3D integrally woven spacer sandwich composites

Woven spacer fabrics of rectangular (RECT), trapezoidal (TPZ) and triangular (TR) cell geometry with woven cross-links were produced and converted to composite forms. The cell height and width were varied in RECT structures, while in TPZ and TR structures, cell wall opening angle was changed keeping all other parameters almost constant. These composites were characterized for their out-of-plane compressive and flexural properties to compare their failure loads and energy absorbing capability. In RECT structures, specific compressive load decreased with increase in cell width (at similar cell height) and increase in cell height (at similar cell width), while the same in TPZ and TR structures increased with increase in cell wall opening angle. Compressive energy per unit volume was observed to be highest at particular cell width in RECT structures, while the same decreased with increase in the cell height of RECT structures. Similarly, energy/volume was higher for TR structure with 42.5 degrees cell wall opening angle. For TPZ structures, energy/volume increased with increase in cell wall opening angle. Flexural properties followed the same trend as that of specific compressive load for these structures. Findings of this research can be used to engineer sandwich composites having woven cross-links with desired mechanical performance.