Effects of Continuous Fiber Insertion on the Strength and Stiffness of 3D Printed Parts

3D printed parts are widely used, which often require high strength and stiffness. However, 3D printed parts face various challenges, properties for printing materials, continuous fiber orientation, moisture absorption, and printing accuracy. Quantitative evaluation of each of these factors will determine appropriate design methods. Therefore, some studies are currently underway to clarify their properties. One example is the insertion of continuous fibers into 3D printed parts, which has been shown to improve strength and stiffness. However, there has been little quantitative evaluation of the insertion orientation and content of continuous fiber. Especially, while the insertion position is theoretically critical to strength and stiffness, there has been no prior approach to evaluate the effect of CF layer insertion position. In this study, we quantitatively evaluated the degree of strength and stiffness improvement by inserting continuous carbon fiber into 3D printed parts during printing. To evaluate the insertion orientation, content and position, we calculated theoretical equations and discussed the discrepancy between theoretical values and experimental results. The results showed that the degree of stiffness improvement achievable in 3D printed parts was clarified in comparison with theoretical values.