For the 3D printed composites, fiber alignment is affected by the direction of melt‐flow during extrusion of filaments and subsequently through the printing nozzle. The resulting fibers orientation and the fiber‐matrix compatibility have a direct correlation with mechanical properties. This study investigates the impact of processing conditions on the state of the carbon fiber types and their orientation on the mechanical properties of 3D‐printed composites. Short and long carbon fibers were used as starting reinforcing materials, and the state of fibers at the beginning and on the printed parts were evaluated. Strong anisotropy in terms of mechanical properties (flexural and impact properties) was observed for the samples printed with different printing orientations. Interestingly, the number of voids in the printed composites was found to be correlated with the fiber types. The present work provides a step towards the optimization of tailored composite properties by additive manufacturing.

Purpose 3D printing techniques such as material extrusion based additive manufacturing provide a promising and cost effective manufacturing technique. However, the main challenges in industrial applications remain with the quality assurance of mass produced parts. The purpose of this study is to investigate the effect of compression moulding as a rapid consolidation method for 3D printed composites, with an aim to reduce voids and defects and thus improving quality assurance of printed parts. Design/methodology/approach To develop an understanding of the inherent voids in 3D parts and the influence on mechanical properties, material extrusion additively manufactured (MEX) parts were post consolidated by using compression moulding at elevated temperature. Findings This study comparatively investigates the influence of carbon fibre length, undergoing process induced scission during filament extrusion and IM and its impact on void content and mechanical properties. It was found that the post consolidation significantly reduced the voids and the mechanical properties were significantly improved compared to the nonconsolidated material extrusion additively manufactured parts, reaching values similar to those of the IM parts. Practical implications Adaptation of extrusion-based additive manufacturing with hybridisation of reliable compression moulding technology transcends into series production of highly adaptive end user applications, such as drones, advanced sports prosthetics, competitive cycling and more. Originality/value This paper adds to the current understanding of 3D printing and provides a step towards quality assurance for mass production.

No abstract

No abstract

Nowadays, there are several methods to obtain simulation models for foams which consider important microstructural features. This research study presents a method to obtain low density foam models directly from computed tomography (CT) data. Finite element meshes are created from CT measurement results of a polypropylene extrusion foam with two different densities. Sensitivity studies with regard to the tension behaviour are performed with the microstructural models. The study shows that the tension behaviour highly depends on the examined area of the foam because the microstructure and density vary through the foam. Furthermore, the simulation results are validated with experimental results. The validation shows that the tension behaviour of the investigated foams characterised by the simulation approach is in good agreement with the experimentally observed behaviour and that specific microstructural characteristics (e.g. anisotropic cell shapes) are captured in the model.

No abstract

No abstract

No abstract