Experimental study of the impact properties of foam based composites reinforced with warp-knitted spacer fabric

In this paper, the impact behavior of polyurethane foam-based composites reinforced with warp-knitted spacer fabric is investigated, experimentally. For this purpose, warp-knitted spacer fabric with different structures such as two different thickness, small and large mesh sizes and position of the meshes facing each other and not facing each other were produced. Then composite samples were fabricated using warp-knitted spacer fabrics as reinforcement, and polyurethane foam as matrix. The physical properties of samples like weight per unit area and fiber volume fraction of composite were measured. The failure energy of prepared samples was measured during quasi-static impact test, and finally low velocity impact with an initial energy of 5 J was carried out on composite samples. The results showed that the impact energy of samples is increased at least tripled by using the reinforcement. The maximum energy absorption is 2.858 J which is related to the samples reinforced with fabric with large mesh, high thickness and not facing of the meshes relative to each other. Generally, the energy absorption on average has been increased 21.2% by increasing the thickness, 9.5% by increasing the size of the meshes from small to big, and 47.3% by changing the position of the meshes from facing to non-facing.