A Concurrent Optimization of Structural Topology and 3D Printing Fiber Path Planning for Continuous Fiber-Reinforced Composites

Continuous carbon fiber-based 3D printers have attracted significant research attention owing to their exceptional mechanical properties and the capability to fabricate complex-shaped structures with drastically shortened production cycles. In this study, a concurrent optimization strategy for structural topology and fiber orientation is developed and implemented for the additive manufacturing of continuous fiber-reinforced composite (AM-CFRC), based on a feature-driven topology optimization method. This method models the target structure as an assembly of sub-components, with fiber orientation aligned to the orientation of these sub-components. Consequently, the additional step of path pattern generation is eliminated preventing path errors typically induced by disordered stress fields. Moreover, the precisely parallel fiber paths enable achievement of maximum fiber volume fractions. To validate the proposed method, several benchmark cases were tested and compared with the original optimization method. Results demonstrate that for the Michell beam, structural stiffness was enhanced by 161%, highlighting the method's significant potential for AM-CFRC structural design. This concurrent optimization of structural topology and 3D printing fiber path planning not only enhances the application potential of CFRCs but also challenges the traditional design paradigms and manufacturing mechanisms of such materials.