Thermo-mechanical analysis of 3D-printed continuous glass fiber reinforced onyx thermoplastic composites

Purpose This study aims to investigate the impact of temperature and fiber volume fraction on the mechanical properties of 3D-printed composites of continuous glass fiber reinforced onyx. Design/methodology/approach Continuous glass fiber reinforced onyx (carbon-filled nylon) 3D-Printed composites have been designed and tested at 40°C, 60°C and 80°C for fiber volume fractions ranging from 13%, 20%, 27%, 33% and 40%. Findings The results of three-point bending tests have shown that at higher temperatures, i.e. greater than the room temperature the 3D-Printed onyx loses its mechanical properties as obvious for thermoplastic composites. However, the inclusion of high temperature glass fibers has improved the mechanical properties of the onyx polymer and its resistance to deformation at higher temperatures. At all temperatures, the increase in fiber fraction increases the yield strength and decreases the elongation of the composite in the strain region below the yield point. At Vf >0.27 the elongation in samples seems less affected by the fiber content. The comparison of the specimen with different fiber volume fractions (Vf) shows that the elongation of the samples at Vf = 0.4, the samples’ response to the applied load has become independent of the temperature above 40°C. Originality/value The experimental and numerically calculated results are well matched, showing the accuracy in the methodology of designing the fiber reinforced onyx composites.