The multi-objective optimization of material properties of 3D print onyx/carbon fiber composites via surrogate model

Abstract

Composite materials play a prominent role in modern engineering. The emergence of composite material technology has brought about a profound impact on almost, if not all industries. The aerospace industry, for instance, benefits greatly from composite materials. With composites, aircraft weight can be reduced while the structural strength is maintained. As with other classes of materials, 3D printing technique allows composite parts of high complexity to be fabricated with great precision. Additionally, with 3D printing, mechanical properties of the resulted part can be accurately customized and controlled by means of varying matrix-reinforcement proportions. As the composite material can be indefinitely customized in 3D printing, it is crucial to evaluate the mechanical properties of the printed specimen. While testing of printed specimens is usually possible, endless production and testing of specimens not only takes time and resources but also leads to extensive experimental waste. In this study, an optimization-based technique is proposed to determine the optimal 3D printing material proportion in order to reduce the need of unwarranted experimental waste and improve the efficiency of composite material selection process. The study aims to investigate the properties of Onyx/Carbon fiber composite material and the optimization of the 3D printing configuration to achieve desirable mechanical properties. The effects of the number of carbon concentric fiber rings and the percentage of infill density of Onyx used in 3D printing were examined. ASTM D3039 tensile tests were performed to obtain mechanical properties of the printed specimen. Considering the values of tensile strength and modulus of elasticity of the printed material, the printing configurations were optimized using a multi-objective non-dominated sorting genetic algorithm II (NSGA-II) with the Kriging model for objective function estimation. From the proposed optimization technique, it has been found that the maximum tensile strength is attained when the number of concentric fiber rings is equal to 3 while the percentage of Onyx infill density falls in the range of 86–90. Contrarily, the modulus of elasticity is maximized when the number of concentric fiber rings is equal to 4 with the percentage of Onyx infill density in the range of 70–75. © 2023 Elsevier Ltd