STEP-NC digital thread for additive manufacturing: data model, implementation and validation

Substantial progress and development in additive manufacturing (AM) technologies have been realised during the last decade but have hardly been implemented on AM systems due to old numerical solutions still used by the AM digital thread, for instance STL (1987) and G-code (ISO 6963, 1982). In this field, more traditional processes like machining have challenged this issue by adopting the Standard for the Exchange of Product model data compliant Numerical Control (STEP-NC) standard that enables advanced and intelligent manufacturing by taking advantage of the full computing performance of numerical controllers in manufacturing machines. This standard integrates the whole digital chain (CAD-CAM-CAPP-CNC-CMM) in a unique file with information on design and manufacturing and enables manufacturing of high-value products directly without numerical data conversion or post-processing. This study presents a new STEP-NC data model for AM technologies developed with the ISO TC184/SC1/WG7 committee. A STEP-NC platform initially developed for machining processes has been adapted to implement and validate the AM data model. It enables AM directly from a STEP-NC file, as well as hybrid manufacturing (AM and machining), and allows integration of several optimisation and simulation modules that extend the possibility of advanced and intelligent AM, for instance in-process manufacturing optimisation.