3D PRINTED CONTINUOUS FIBRE COMPOSITE RESEARCH AT DEAKIN UNIVERSITY: DESIGN AND ANALYSIS METHODS FOR UD, HYBRID AND PSEUDO-WOVEN PLY ARCHITECTURES

At Deakin University we have been researching the performance of continuous fibre 3D printed composite structures and a summary of three research activities related to this research theme are provided herein. 3D printed continuous fibre composites can be used to realise significant gains in stiffness and strength compared to an equivalent component fabricated using a neat thermoplastic. To investigate the performance of these materials both commercially available and customised printers were used to fabricate composite laminates and the behaviour of these laminates evaluated experimentally. Finite element and analytical models were used to predict the mechanical response. These approaches were originally developed for thermoset matrices, however, the models have shown to be capable of predicting the behaviour of 3D printed carbon fibre and hybrid carbon-fibreglass thermoplastic composites. These validated models can be used to generate design charts to identify feasible UD and semi-woven textile architectures, thereby, allowing designers to tailor the ply architecture and stacking sequence to meet specific design requirements.

Additive Manufacturing-Based In Situ Consolidation of Continuous Carbon Fibre-Reinforced Polycarbonate

Continuous carbon fibre-reinforced thermoplastic composites have convincing anisotropic properties, which can be used to strengthen structural components in a local, variable and efficient way. In this study, an additive manufacturing (AM) process is introduced to fabricate in situ consolidated continuous fibre-reinforced polycarbonate. Specimens with three different nozzle temperatures were in situ consolidated and tested in a three-point bending test. Computed tomography (CT) is used for a detailed analysis of the local material structure and resulting material porosity, thus the results can be put into context with process parameters. In addition, a highly curved test structure was fabricated that demonstrates the limits of the process and dependent fibre strand folding behaviours. These experimental investigations present the potential and the challenges of additive manufacturing-based in situ consolidated continuous fibre-reinforced polycarbonate.

Review of mechanical properties of and optimisation methods for continuous fibre-reinforced thermoplastic parts manufactured by fused deposition modelling

A new way of manufacturing continuous fibre-reinforced plastics is the embedding of fibres in the filament of a 3D printer. This method could be used in manufacturing composite materials with a thermoplastic matrix containing glass, Kevlar and carbon fibres. This paper provides an overview of research on the mechanical and physical properties of these parts as well as optimisation approaches of additively manufactured thermoplastics. Furthermore, applicable testing and analysis methods and their corresponding standards are included. Several studies, which represent the current state of the art, are reviewed in detail for the analysis of the mechanical performance of different fibre reinforcements. In addition, an overview of different optimisation approaches is given. The ultimate tensile strength of Kevlar and glass fibre-reinforced parts are similar to those of common Aluminium alloys whereas the carbon fibre reinforced parts outperform their aluminium counterparts. Major performance limitations include a poor adhesion between layers as well as a high air void ratio.