A review and outlook of airframe digital twins for structural prognostics and health management in the aviation industry

The Airframe Digital Twin (ADT) framework was conceived over a decade ago as a revolutionary way to realise condition-based maintenance within the defence aviation field. Since then, this concept has witnessed significant progress not only in terms of its scope and areas of application, but also in the fidelity of the virtual models used to represent physical systems. This paper sheds light on the progress and evolution of the ADT framework and methodologies since 2011 through a systematic literature review. Based on this review, it is understood that the progress in ADT places the aerospace industry on a path towards achieving Structural Prognostics and Health Management (SPHM), nevertheless more work needs to be done. This paper proceeds on evaluating the remaining challenges in the development of the ADT for SPHM, particularly in the context of fatigue and corrosion as the main forms of structural degradation. Modelling of the environmental and operational conditions, multiphysics, and multiscale interactions are highlighted. A further review on the outlook for ADT in the civil aviation industry is presented through comparisons between current industrial regulations and the state-of-the-art in the scientific community, and focus areas for future works in developing the ADT for SPHM are identified.