Concurrent topology and path optimization of manufacturable fiber-reinforced structures following hybrid concentric printing paths

• Introduces a novel framework for concurrent topology and path optimization tailored for fiber-reinforced composite structures. • Incorporates manufacturable layer-by-layer concentric printing paths directly into the structural design process. • Ensures compatibility between optimized fiber orientations and realistic deposition constraints, eliminating the need for post-processing. • Demonstrates the approach through both numerical examples and experimental validation via three-point bending tests. • Enables streamlined integration of structural optimization with digital fabrication workflows for fiber-reinforced composite structures. Fiber-reinforced additive manufacturing, also known as 3D printing, has attracted growing attention in recent years for its potential to fabricate lightweight structures through a layer-by-layer building process. However, anisotropic properties of materials resulting from specified layer-by-layer printing paths, e.g., commonly used hybrid concentric printing paths, coupled with structural geometry, lead to challenges in topology optimization of fiber-reinforced composite (FRC) structures. This paper presents a new optimization algorithm that can find optimal topologies of FRC structures and layer-by-layer hybrid concentric printing paths simultaneously. First, we develop the finite element model for a given FRC structure where the orientations of FRCs within each element are determined by fabricable layer-by-layer hybrid concentric printing paths. The close agreement between numerical and experimental results confirms the simulation model’s accuracy and reliability. Then, an optimization algorithm is developed to concurrently update structural topology and printing paths iteratively until an optimal structural topology and compatible hybrid concentric printing paths are achieved. The numerical examples and three-point bending flexural test are presented to demonstrate the effectiveness of this manufacturing-oriented optimization approach and its advantages over the post-processed printing paths based on the conventional topological optimized designs. The research promises the seamless integration of optimization design and fiber-reinforced additive manufacturing.