Rheology-Informed Simulation Framework for Predicting Fiber Orientation in Material Extrusion Process

초록

Material extrusion in additive manufacturing (AM) is gaining attention owing to its suitability for high-throughput applications across various industries. In this study, we focus on a pellet-based material extrusion process, which employs pelletized feedstock instead of filament. This approach is especially advantageous for the fabrication of composite materials, such as carbon fiber reinforced plastic (CFRP), using thermoplastic materials. However, irregular fiber orientation during the extrusion process can lead to anisotropic properties that can adversely affect the mechanical strength and overall material quality. Addressing these challenges necessitates the precise control of the fiber orientation to ensure the reliability of the composite properties. This study proposes a rheology-informed simulation framework for predicting the fiber orientation within the nozzle during the extrusion process. The approach is based on rheological flow characteristics, which are sequentially combined with the fiber orientation tensor method to estimate fiber alignment under varying process conditions. Experimental data were obtained under identical processing conditions to validate the simulation. The results demonstrate that the proposed approach can reliably predict the fiber orientation with a high degree of accuracy. This represents a marked improvement over the existing method, raising accuracy from about 90% to 96%. Therefore, this study provides valuable insights for optimizing fiber-reinforced composite quality in AM applications.

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