航空发动机盘件径轴向裂纹底波监控超声检测方法研究

Research on Ultrasonic Back-wall Echo Monitoring Method for Radial-axial Crack of Aircraft Engine Disk

针对某航空发动机盘件中的径轴向裂纹,采用不同焦距的5MHz、10MHz聚焦探头和平探头,分别在0°,1°,2°,3°的声束入射角度下进行检测试验,通过对入射角度以及探头类型、频率、焦距等参数的优化,建立了径轴向裂纹的底波监控超声检测方法。研究发现:与垂直入射相比,小角度纵波斜入射底波监控超声检测方法可提高超声波对裂纹的敏感程度;使用焦距为89mm的10MHz聚焦探头,并使声束以2°入射角斜入射可得到最佳检测效果,试验结果与数值模拟具有良好的一致性。

Experiments were performed by focusing and flat probes with different focus lengths and frequencies under the incidence angles of ultrasonic beam 0°,1°,2°and 3° respectively. Based on the optimization of the incidence angle as well as probe parameters, an ultrasonic back-wall echo monitoring method was established for the detection of radial-axial crack of aircraft engine disk. The research reveals that in contrast with the normally incident wave beam, performing the ultrasonic back-wall echo monitoring method with a small angle incidence longitudinal wave can enhance the sensitivity of ultrasonic evaluation of cracks. The optimal results can be ob- tained by using a 10MHz ultrasonic focusing probe with the focus length of 89ram and incidence angle of 2°. The experiments show good agreements with the numerical simulation results. The study results are the great reference values to the application of ultrasonic back-wall echo monitoring method for the evaluation of radial-axial cracks.