Deposition path planning for material extrusion using specified orientation fields

The thermal characteristics of the material extrusion additive manufacturing (AM) process produce weak bonds between layers and adjacent depositions, resulting in an overall anisotropic mechanical performance. Design for AM guidelines advise printing load-bearing parts such that load is applied strictly along the deposition paths, but this can be difficult to achieve with complex loading conditions. Recent works have explored toolpath generation techniques capable of generating deposition paths that are aligned with complicated load paths, but the methods rely on assumptions about the shape of the load paths relative to the geometry. In this paper, the authors present an algorithm for generating deposition paths for any arbitrary geometry and anticipated load paths. Deposition paths are planned using a streamline placement algorithm - commonly used for visualizing fluid flow fields - that treats the load paths as a velocity field. The algorithm is demonstrated on an example geometry, and the volumetric coverage of the resulting toolpath is compared to a toolpath generated using a standard toolpath planning technique. Through this comparative study, it is demonstrated that the toolpath resulting from the authors' proposed algorithm is able to follow the load paths while still achieving similar volumetric coverage to the standard toolpath.