%A Kai SONG, Chi ZHANG, Chenhui YAN, Ning NING, Junling FAN, Rongbiao WANG %T Reliability of aero-engine wheel model assisted eddy current testing based on two-parameter representation %0 Journal Article %D 2023 %J Acta Aeronautica et Astronautica Sinica %R 10.7527/S1000-6893.2022.27866 %P 227866-227866 %V 44 %N 13 %U {https://hkxb.buaa.edu.cn/CN/abstract/article_19319.shtml} %8 2023-07-15 %X

The key index a90/95 of Probability of Detection (POD) is used in the design of aero-engine disk damage tolerance. Aiming at the problem that a90/95 of the POD study on single size parameters causes inaccurate capability representation of the eddy current detection system, this paper proposes a Model-Assisted Probability of Detection (MAPOD) model based on two-parameter representation by analyzing the influence of length and depth factors of manual grooving defects on POD. The model assumes that the eddy current response amplitude of the defect described by the two-dimension parameter vector x follows a normal distribution. The simulation and eddy current test response data are substituted into the maximum likelihood estimation to obtain the model parameters, and the reliability parameters characterizing the detection system are then calculated. After analysis of the eddy current signal generated by the TC4 defect, the influence degree of the number of defects on the single parameter model and the improved model is compared. The results show that the improved MAPOD model can characterize the Nondestructive Testing(NDT) system capability more accurately with fewer samples compared with the single-parameter POD model. Finally, the detection capability of the aero-engine wheel eddy current testing system is evaluated with a small number of defect samples, providing important basis for aero-engine maintenance cycle and DamageTolerance (DT) design.