导航

ACTA AERONAUTICAET ASTRONAUTICA SINICA

    Next Articles

Research on MAPOD of aero engine disc eddy current testing based on two-parameter characterization

  

  • Received:2022-07-28 Revised:2022-09-16 Online:2022-09-22 Published:2022-09-22

Abstract: 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 POD study on single size parameter will cause inaccurate capability representation of eddy current detection system, by analyzing the influence of length and depth factors of manual grooving defects on POD, A mod-el-assisted Probability of Detection (MAPOD) Model based on two-parameter representation is proposed. The model assumes that the eddy current response amplitude of the defect described by the two-dimension parameter vector x follows N(μ(x),σ(x)), and the simulation and eddy current test response data are substituted into maximum likelihood estimation to obtain the model parameters, and then the reliability parameters characterizing the detection system are calculated. By analyzing 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: Compared with the single-parameter POD model, the improved MAPOD model can characterize the NDT system capability more accurately with fewer samples. Finally, the detection capability of the aero-engine wheel eddy current testing system was evaluated with a small number of defect samples. It provides an important basis for aero-engine maintenance cycle and Damage Tolerance (DT) design.

Key words: turbine disc, Eddy current testing, Two-parameter, Model assisted method, Nondestructive testing reliability

CLC Number: