A SHM damage diagnosis model evolution mechanism for individual aircraft structure

Abstract. The concept of aircraft health management is evolving from conventional fleet-based management to individual aircraft-based management. Accurate damage diagnosis with guided wave (GW)-based structural health monitoring (SHM) is of great significance for individual aircraft in service. However, both the damage propagation and monitoring of individual aircraft structures are affected by various uncertainties, such as time-varying environmental and operational conditions, different flight missions, and different damage morphologies. Consequently, employing a prior trained damage diagnosis model inevitably introduces errors, thereby limiting the engineering applicability of SHM. To achieve more reliable damage diagnosis for in-service aircraft structures, this paper proposes a whole lifetime data-based damage diagnosis model evolution mechanism. Multi-source data from the design, service, and maintenance stages are used to continuously evolve the probabilistic damage diagnosis model, enabling it to track the specific damage propagation. The proposed method is validated through fatigue crack monitoring experiments of a typical aircraft load-carrying structure. The results demonstrate that it can significantly improve the damage diagnosis performance for in-service aircraft structures under the influence of uncertainties.