Tensile mechanical properties of composite materials with continuous fiber produced by additive manufacturing

Abstract

Additive manufacturing of composites parts reinforced with continuous fibers is emerging as a versatile process, capable of producing complex computer-aided design models by fabricating parts adding material layer by layer. Fused deposition modelling using polymeric materials has been used to produce prototypes, with the constraint of the strength of the material. Recently, the use of continuous fiber reinforcement has provided an alternative for the production of load-bearing functional parts. Current international standards for the characterization of composite materials from mechanical tests are established for parts manufactured by conventional methods, such as, manual molding, injection or coatings. Moreover, the standards do not specify procedures for composite materials produced by additive manufacturing. The objective of this work is to evaluate the performance of the reinforced composite materials produced by additive manufacturing for tensile tests under ISO and ASTM standards, and compare the results in terms of the topology of the material configuration. Average values of the tensile strength for composite materials having a triangular nylon matrix reinforced with fiberglass were obtained within the range of 205 MPa to 234 MPa, with deformations no greater than 0.020 mm. These values are higher than the strength provided by additive manufacturing using materials such as polylactic acid and acrylonitrile butadiene styrene.