Digital Twins for Metallic Additive Manufacturing in Marine Engineering

The aim of this study was to explore the potential of using digital twins to enhance the accuracy and reliability of additive manufacturing under marine operating conditions. A comprehensive theoretical and analytical framework was developed for creating a digital twin for wire arc additive manufacturing (WAAM) in marine engineering, in which external destabilising factors were taken into account. It was found that without digital control, under conditions involving vibrations (0.2–3 Hz), temperature differentials of up to 500°C and platform instability, the risk of defect formation was increased. The numerical values reported here were derived from modelling results, a review of the literature, and analytical generalisation of published WAAM and digital twin data, rather than from new full-scale offshore experiments. The use of digital twins can enable real-time monitoring of parameters such as the wire feed speed (2–10 mm/s), arc power (300–1200 W), and feed angle (20–45°), thus allowing the heat transfer to be optimised and residual stresses to be reduced. Modelling-based synthesis and analytical generalisation of published data show that the implementation of this framework reduces the number of defective zones from 18 to four per component, decreases the energy consumption per part from 6.2 to 4.1 kWh, and improves the dimensional repeatability from ±0.9 to ±0.25 mm. Digital twins also allow the printing trajectory to be adapted to current conditions through integrated sensors and deformation modelling, thereby ensuring operational reliability on offshore platforms. The use of digital twins is therefore critically important for improving the accuracy, energy efficiency, and operational reliability of WAAM in marine environments.