MECHANICAL PROPERTIES OF 3D PRINTED CONTINUOUS CARBON FIBER/ POLYPROPYLENE LATTICE CORE COMPOSITE SANDWICH STRUCTURE

The production of functional parts with 3D manufacturing techniques has started to disclose fascinating studies. Although only thermoplastic filaments were initially used, fiber-reinforced composite parts can be produced using developing techniques. This study investigated the quasi-static and dynamic mechanical performance of 3D printed continuous Carbon Fiber Reinforced (CFR) composite sandwich panels. Sandwich panels were designed with a prismatic lattice core between CFR composite facesheets. Continuous CFR Thermoplastic (Polypropylene (PP)) Monofilament Composites (CCTMC) were used to produce sandwich structures. CCTMC sandwiches were produced with a laboratory-scale production system, including thermoplastic extruder and mold designed specifically. Facesheets of sandwiches were manufactured in a hot compression mold as [0°/90°/0°] stacking sequence as three-layers using the same CCTMCs. The sandwich panels were fully recyclable and ultra-lightweight, and pyramidal-shaped truss-type lattice cores were placed as the core of the structure. Test results showed test specimens had stand ~270 kN peak force in the compression test and ~240 kN peak force in 3-point bending, and the deformation in the structure occurred when the mono composite element reached the buckling limit. In the dynamic 3- point bending, the peak force value increased approximately 2 times and reached 450 kN due to the strain-rate dependence of the material.