Tolerancing and Verification of Additive Manufactured Lattice with Supplemental Surfaces

Additive manufacturing (AM) has enabled the production of complex geometries such as conformal lattices, topology optimized shapes, and organic structures. These complex geometric shapes must sometimes meet functional requirements, including (1) following specific curves or surfaces and (2) being bounded by specific surfaces. Mechanisms such as Theoretical Supplemental Surfaces (TSS) have been proposed for tolerancing of such geometric shapes, though challenges remain with inspection and validation requirements. A Theoretical Supplemental Geometry (TSG, including curves – TSC, surfaces – TSS and volumes – TSV) concept is introduced. To address these measurement and verification challenges, Derived Supplemental Surfaces (DSS) are introduced. The verification of a TSS specification using 3D scanning and DSS is demonstrated on a lattice surface using Chebyshev and Least Squares fitting.