Process planning for adaptive contour parallel toolpath in additive manufacturing with variable bead width

Lightweight structures with slender features and thin walls can be fabricated by the additive manufacturing process. The fabrication process utilizes a contour parallel toolpath, where sets of parallel contours are offset from the boundaries of a geometric structure at predefined intervals to deposit the material layer by layer. Currently, these intervals are set to be constant, which limits its capability to produce near net-shape parts. In recent research, the feasibility to fabricate parts using contour parallel toolpaths with variable bead widths has been explored to increase the production speed, to improve the geometry accuracy, and to manufacture void-free parts. However, existing process planning methods are computationally inefficient and challenging to implement. To resolve these issues, this paper proposes a comprehensive process planning framework for adaptive contour parallel toolpath with variable bead widths. More specifically, this framework includes a toolpath planning algorithm using the level-set method and a process planning algorithm for generating the desired bead geometry using a Gaussian process regression model. To validate the proposed framework, a case study has been demonstrated in the fabrication of benchmark features with a wire and arc additive manufacturing process.