Compression and Bending Properties of Short Carbon Fiber Reinforced Polymers Sandwich Structures Produced via Fused Filament Fabrication Process

Abstract

Additive manufacturing, through the process of thermoplastic extrusion of filament, allows the manufacture of complex composite sandwich structures in a short time with low costs. This paper presents the design and fabrication by Fused Filament Fabrication (FFF) of composite sandwich structures with short fibers, having three core types C, Z, and H, followed by mechanical performance testing of the structures for compression and bending in three points. Flatwise compression tests and three-point bending have clearly indicated the superior performance of H-core sandwich structures due to dense core structures. The main modes of failure of composite sandwich structures were analyzed microscopically, highlighting core shear buckling in compression tests and face indentation in three-point bending tests. The strength–mass ratio allowed the identification of the structures with the best performances considering the desire to reduce the mass, so: the H-core sandwich structures showed the best results in compression tests and the C-core sandwich structures in three-point bending tests. The feasibility of the FFF process and the three-point bending test of composite wing sections, which will be used on an unmanned aircraft, have also been demonstrated. The finite element analysis showed the distribution of equivalent stresses and reaction forces for the composite wing sections tested for bending, proving to validate the experimental results.

Polymeric composites in extrusion‐based additive manufacturing: a systematic review

“…170 Considering the same reinforcing material, more expressive efforts have also focused on investigating how the overall extrudate behavior is affected by voids, 80 process parameters and deposition patterns, 102,105,107,109,124,151,161,167,177,181 fiber settings, 150,154 filament processing conditions, 163 and magnetic fields. 133 The accessibility, ease of processing, and desirable mechanical properties of carbon fiber/ polymer composites for 3D printing have led to the usage of these materials for developing prosthetic fittings, 119 landing gears for unmanned aerial vehicles, 131 sandwich structures, 174 and variable-stiffness laminates. 111 In terms of optimization strategies for printing CFRPs, Kim and Kang 143 proposed a systematic approach for tool path generation.…”

“…Automotive and aerospace industries (n = 5) Microsatellite structures 104 Landing gears 131 Wing sections from UAVs 174 Car headlight lugs 176 Aerospace structures 104,131,174 Automotive repair 176 3D printing in an extraterrestrial environment (vacuum conditions) 66 Biomaterials, biomedical or tissue engineering (n = 11) Scaffolds 67,138,157,173 Bone grafts 67,71,138,157,173 Assistive technology 119 Implants for craniofacial bone reconstruction 68 Piezoresistive sensors 90,129 Dielectric lens and 5G antenna 108 Photonic crystals 130 Tag coils for radio frequency identification 87 Circuit carriers 94 Low-cost sensors 83 Electromagnetic shielding 117 Biosensors and soft robotics 84 Human motion monitoring 129 Rigid electronic structures 87 Radiofrequency and telecommunications 108 Microwave photonic devices 130 Conductive parts and molds 172 Electronic assemblies 94 Structural health monitoring. 90 Functional parts and tooling (n = 8)…”

Tribological characteristics of ABS structures with different infill densities tested by pin-on-disc

“…[5][6][7][8] The other polymer used in the FFF system is PETG which has also been investigated in terms of mechanical, geometrical, and biomedical properties by academic researchers. 6,[9][10][11] In addition, some materials such as ceramic, 12,13 carbon, glass fiber, 12,[14][15][16] flax fiber, 17 graphene, hydroxyapatite, and bio glass [18][19][20][21] have been used to create composite polymers. 3D printed samples fabricated with these composite polymers were evaluated for dielectric, compression, bending, tensile strength, and biological properties.…”