Non-destructive evaluation of 3D-printed fibre-reinforced composite materials mechanical behaviour

Fused filament fabrication (FFF) is the most widely used additive manufacturing (AM) technique to produce fibrereinforced polymer matrix composites, due to their low wastage, geometric flexibility and ease of use. Composite materials generally have superior properties such as being stiffer and more robust than conventional materials at a reduced weight leading to their application in a wide variety of sectors (aerospace, automotive etc). However, composites manufactured in this way are highly susceptible to defects such as high void content and poor bond quality at the fibre and matrix interfaces. These defects stop fibre-reinforced composite materials manufactured this way meeting industry standards and being used for structural applications. In the present work, a combination methodology of acoustic emission (AE) alongside tensile testing has been developed to investigate the structural integrity and mechanical performance of AM fibre-reinforced composites. Pure polymer samples and short carbon fibre reinforced composites were manufactured, and their mechanical properties were observed.