Research on Process Planning for Hybrid Additive‐Subtractive Manufacturing of S‐Shaped Carbon Fiber Composite Structures

For complex short‐fiber‐reinforced composite components, there are problems of additive deposition continuity and subsequent subtractive machining accessibility in multi‐axis hybrid additive‐subtractive manufacturing (HASM). This study proposes a process planning method that integrates variable‐direction slicing with accessibility‐driven partitioning. First, under interlayer constraint conditions, variable‐direction slicing layers are generated based on principal component analysis (PCA) plane fitting, and smooth multi‐axis deposition is achieved by updating the build direction layer by layer. On this basis, a machining accessibility evaluation model based on the continuous tool‐axis field of slice contours is established. Accordingly, a top‐down accessibility‐driven geometric partitioning strategy is developed to realize partition‐based hybrid additive‐subtractive process planning for complex structures. The experimental results demonstrate that the proposed method maintains deposition continuity in complex curved regions while ensuring accessibility for subsequent machining. The error distribution in the main curved regions and sub‐block transition regions of the fabricated part remains stable. The proposed method can effectively improve the surface quality of the fabricated part, reducing the surface roughness by 43.6%. Meanwhile, by reducing the number of sub‐blocks and process switching operations, the non‐processing time is decreased by 38.6%. This provides a new process route for the multi‐axis collaborative manufacturing of short‐fiber‐reinforced composite complex curved structures.