Probability of detection and anomaly distribution modeling for surface defects in tenon-groove structures of aeroengine disks

To ensure the structural integrity of life-limiting component of aeroengines, Probabilistic Damage Tolerance (PDT) assessment is applied to evaluate the failure risk as required by airworthiness regulations and military standards. The PDT method holds the view that there exist defects such as machining scratches and service cracks in the tenon-groove structures of aeroengine disks. However, it is challenging to conduct PDT assessment due to the scarcity of effective Probability of Detection (POD) model and anomaly distribution model. Through a series of Nondestructive Testing (NDT) experiments, the POD model of real cracks in tenon-groove structures is constructed for the first time by employing the Transfer Function Method (TFM). A novel anomaly distribution model is derived through the utilization of the POD model, instead of using the infeasible field data accumulation method. Subsequently, a framework for calculating the Probability of Failure (POF) of the tenon-groove structures is established, and the aforementioned two models exert a significant influence on the results of POF.