Thermomechanical behaviour of 3D-printed carbon, glass, and aramid fibre-reinforced composites under heat exposure: Interlaminar failure perspective

This study investigates the interlaminar shear strength (ILSS) of 3D-printed continuous carbon, glass, and Kevlar fibre-reinforced polymer (CFRP, GFRP, and AFRP) composites with an Onyx matrix exposed to elevated temperatures up to 200 °C. ILSS of CFRP and AFRP increased steadily up to 170 °C, peaking at 196 % and 203 % of baseline, respectively. This is driven by annealing and enhanced fibre–matrix reconsolidation. Both materials maintained high ILSS retention at 200 °C, with CFRP at 183 % and AFRP at 173 %. In contrast, GFRP exhibited a weaker response, with variable retention and a decrease in ILSS to 84 % of its baseline at 200 °C. These findings highlight the superior performance of CFRP and AFRP, which is attributed to enhanced interlaminar bonding and the thermal stability of their matrices, while GFRP’s performance was hindered by thermal cracking. The results show the importance of fibre selection for high-temperature applications, with CFRP demonstrating the best overall performance.