某型飞机水平尾翼疲劳试验的声发射实时监测

介绍了某型飞机水平尾翼功能试验过程中关键部件(包括不可接近部件)疲劳损伤的声发射(AE)实时监测技术.在强冲击、高振动背景噪声下,基于对模拟声发射源和背景噪声信号特征的分析,对采集数据进行了预处理,提高了数据的信噪比.对预处理后的AE信号特征参数进行趋势分析,结果表明,在长时间的疲劳试验过程中,由于试验环境的变化,背景噪声也发生相应的变化,AE信号特征参数的变化趋势能正确反映背景噪声变化的随机性和非稳态性.以半轴为例,AE信号特征参数(Hits)的趋势变化反映出半轴的疲劳损伤历程;通过AE信号的波形分析,基本确定了半轴初始疲劳损伤的形成时间和两对称的疲劳损伤源.

Acoustic Emission Real-Time Monitoring for Fatigue Damage to Horizontal Tails of a Certain Plane During Functional Test

The acoustic emission(AE) real-time monitoring for fatigue damages to the horizontal tails and some inaccessible components was carried out during the functional test for a certain plane.In a noise background due to severe shock and vibration,the simulated AE sources and background noise were analyzed to pre-process the acquired data properly so as to enhance greatly the signal-to-noise ratio(SNR).Then,a trend analysis was made for the characteristic parameters of AE signals.The test results showed that in a long-time fatigue test process the background noise may change correspondingly to the change in ambient conditions,and the change in the trend analysis of the characteristic parameters of AE signals will therefore reflect properly the randomness/nonsteadiness in the changing background noise.Illustrated with the half-shaft fatigue damage,the trend of the characteristic parameters of AE signals(in hits) can reflect successfully the history of half-shaft fatigue damage.Thus,the time the initial fatigue damage starts and two symmetrical sources of fatigue damage can both be determined basically by analyzing the waveform of AE signals.