Abstract:

Currently, the design of lattice structures for additive manufacturing is disconnected from the subsequent slicing. Traditional methods rely on generic slicing algorithms based on STL (Standard Triangle Language) models, in which the entire lattice structure must first be discretized into a triangular mesh, and contours are then generated by intersecting the mesh with slicing plane. However, lattice structures contain a large number of members, resulting in massive STL model data volumes. Furthermore, the approximate representation of triangular patches is prone to introducing geometric errors, leading to reduced slicing accuracy. At the same time, the intersection calculation requires traversing a large number of redundant triangular patches, resulting in low computational efficiency and making it difficult to meet the demand for rapid preprocessing of large-scale lattice structures. To address these issues, a direct slicing method tailored for lattice structures was proposed to avoid the intermediate conversion to an STL model. This method first abstracted each connecting rod into a cylindrical or conical geometric shape and directly utilized the topological position data of the members generated during the design phase. to establish an analytical geometric relationship between the cutting plane and the members. By applying the closed-form formula for the intersection of a spatial line and a quadratic surface, the method directly calculated the intersection contour between the members and the cutting plane, yielding precise cross-sectional shapes. Geometric distortion caused by triangular-mesh discretization was thereby avoided, and improves contour accuracy was improved. To optimize computational efficiency, data-mapping technology was introduced to transform the analytical solution of conic-section contours into linear mappings and matrix operations based on the unit circle. By pre-computing transformation matrices, this method enabled contour reconstruction for each slice layer by simply updating the member center coordinates, effectively eliminating redundant calculations and accelerating the processing of large-scale grids. Furthermore, for complex contours formed by the intersection of multiple members at nodes, a polygon merging operation was employed for post-processing to eliminate contour intersections and redundant edges, thereby generating continuous, self-intersection-free slice contours. Experimental results demonstrated that the proposed algorithm exhibited good feasibility and effectiveness, capable of improving the efficiency and accuracy of preprocessing for additive manufacturing models of lattice structures.

Key words: lattice structures, direct slicing, additive manufacturing, data mapping, design-manufacturing integration