声发射技术在全尺寸飞机疲劳试验中的应用

过去九年,,在对两类三代机的全尺寸疲劳试验中实施了全程声发射监测。采用了以声发射为中心的裂纹综合监、检测方法,对一些关键构件的疲劳裂纹实施早期预报,并用其它无损检测方法加以验证,为试验的顺利进行奠定了重要基础,为确定和延长这两类飞机的机群寿命发挥了重要作用。在对第一类三代机的试验中,发展了过去所用的声发射信号处理技术,在大量获取试验中的声发射信号时,有意识地将信号分成一系列有序的信号子集,分别反映一定的飞机受力(载荷)状态,在此基础上再采用空间滤波等技术获得感兴趣结构位置处的信号子集。对子集再采取基于统计分析原理的趋势分析和相关分析技术,获取监测位置的状态,以及试验机的“健康状态”。这一方法在另一类三代机的试验中再次发挥作用,显示了生命力。最终结果是两类三代机的机群寿命均有50%以上的提高,说明声发射技术具有广阔的应用前景。

Application of Acoustic Emission Technique to theFull Scale Aircraft Fatigue Test

Full scale aircraft fatigue test was carried out for two types of military aircrafts in the past 9 years in order to determine and prolong their effective lives. Integrated crack monitoring and identification centered by acoustic emission (AE) was employed to predict and issue early warning for critical structures. An effective data evaluation means was developed by re-organizing the recorded data through disintegrating the original data into sub data sets according to the loading conditions. Further processing method was carried out by spatial filtering and other filtering measures, followed by trend analysis and correlation analysis of statistically averaged these sub data sets to evaluate the states of key structures and health condition of the aircraft, respectively. This data evaluation method was applied to the fatigue test for another type of aircraft and once again its efectiveness was proven. The final outcome was the more than 50% increment of the original lives for the two types of aircraft groups. It means that acoustic emission has great potential in future engineering applications.