航空发动机涡轮叶片裂纹的阵列涡流检测仿真

Simulation on Aero-engine Turbine Blade Cracks Detection Based on Eddy Current Array

阵列涡流检测技术因检测范围大和适应性强等诸多优点适合航空发动机涡轮叶片的快速检测。本文建立了发动机涡轮叶片裂纹阵列涡流检测的有限元模型,研究涡轮叶片的叶盆和叶背两种曲面下阵列涡流传感器的检测信号特征。仿真结果表明:当涡流探头与叶身的提离距离不变时,检测线圈的感应电动势随凸面、平面和凹面的次序逐渐增加;检测纵向裂纹时检测线圈电动势敏感度可达激励线圈的12.5倍,其电动势波峰和波谷的距离可表征纵向裂纹的长度且误差小于1.0mm,而横向裂纹深度也与检测线圈电动势的波谷幅值成单调递减关系,仿真结果可望用于指导发动机涡轮叶片的工程检测实践。

The eddy current array testing technique features a large range of detection,strong adaptability,and many other advantages,which make it suitable for rapid aero-engine turbine blade detecting.In this paper a finite element eddy current array testing model of engine turbine blade cracks is established,and the signal characteristics are studied of the eddy current arrayed sensors for the concave and convex surfaces of the turbine blades.The simulation results show that the electromotive force of the detecting coil increases gradually with convex,plane and concave surfaces when the lift-off distance between the eddy current probe and the blade body is constant.The sensitivity of detecting coil electromotive force for longitudinal cracks can reach 12.5 times that of the excitation coil,and the distance between the peak and trough electromotive force can represent the length of the longitudinal crack with an error of less than 1.0 mm.The transverse crack depth and the trough amplitude of the detecting coil electromotive force show a relationship of monotone decreasing.The simulation results can be used to guide engine turbine blade testing in engineering practice.