Tensile Properties of Additively Manufactured Thermoplastic Composites Reinforced with Chopped Carbon Fibre

Abstract

3D printing allows controlled deposition of composite components, which the user defines by the modification of the printing parameters. The article demonstrates that all observed printing parameters (infill type, infill orientation) influence the tensile test results of nylon reinforced with chopped carbon fiber. The highest tensile strength obtains specimens with the maximum number of walls around the circumference. The plastic region of the tensile diagram differs significantly with the change of material orientation in the structure, as the specimens with material deposited 45/−45 to the load axis have four times greater tensile strains and 20% higher tensile stresses than 0/90. The assessment of results reveals the significant difference between deformations at break and permanent deformations. In addition, the permanent lateral strain reaches up to 20%. Finally, the article consists of a brief assessment of the printing parameters (printing time, weight) of individual series. The future modelling in FEA software requires additional experiments to verify the viscoelastic properties of the material.

Challenges in Tensile Testing of Thermoplastic Composites Reinforced with Chopped Carbon Fibre Produced by Fused Filament Fabrication Method

“…In the case of the 0/90 strategy, the disadvantage is that approximately half of the laminates are oriented perpendicular to the load axis, which means a significant reduction of strength due to the presence of bonds between adjacent filaments, which are relatively weak in the case of extrusion methods of additive technologies. The results show a considerable directional dependence on mechanical properties, whereas objects printed using this technology behave orthotropically [38][39][40]. Typically, the worst tensile properties are obtained in the layering direction of the laminates [40][41].…”

“…6). However, the deposition around the specimen circumference has a strengthening effect and, despite the occurrence of stress concentrators, leads to the highest measured tensile strength values [34].…”

“…5). Experience shows that under certain circumstances, failure often occurs in the area of the rounding [34]. The cause is the presence of a stress concentrator.…”

“…8). There are many material arrangement strategies -for example, hexagonal infill, triangular infill, 45/-45, 0/90 [34,[37][38]. Most of them must preset the user manually in the slicing software (infill pattern).…”

Deformation Behavior of Single Carbon Fibers Impregnated with Polysulfone by Polymer Solution Method

“…At the moment, there is an active study of the deformation behavior of composite material thermoplastic polymer-carbon fiber, interest in which is largely due to the development of additive technologies [ 8 , 16 , 41 , 42 , 43 , 44 , 45 ]. In a number of works, composite materials based on thermoplastics and thermoplastics are compared.…”