Evolution of Computational Approaches for Engine Structural Integrity in Life Cycle Management: From Traditional Methods to Digital Twin Technology

This review examines the evolution and current role of life cycle management for aircraft engines under the Engine Structural Integrity Program (ENSIP) framework. ENSIP has been instrumental in aviation by providing frameworks for damage tolerance, fracture control, and fatigue life evaluation in both military and commercial aircraft engines. The paper synthesises the transition of ENSIP from traditional damage-tolerance and safe-life methodologies toward data-driven, computationally enhanced frameworks. The core novelty lies in the structured integration of ENSIP principles with advanced computational approaches, including Finite Element Modelling (FEM), Artificial Intelligence (AI), Prognostics and Health Management (PHM), digital twin technologies, and hybrid frameworks. In addition, the review organises these approaches into an ENSIP-centric taxonomy and qualitatively discusses their relative maturity, practical readiness, and existing research gaps for life-cycle decision support. Moreover, the review addresses persistent technical, operational, economic, and management challenges, offering context for future maintenance frameworks. Ultimately, by integrating conventional engineering with advanced digital technologies, this review underscores ENSIP’s dynamic contribution to improving aviation safety, advancing maintenance practices, and achieving higher standards of operational performance.