摘要
针对提高声发射源定位精度的需要,提出了利用小波变换从宽带非平稳声发射信号中提取稳定的窄带响应信息的方法,可降低环境噪声和波速色散效应的影响;进一步根据Hilbert变换提取窄带信号的包络,可根据第一个包络峰值正确判定应力波到达时刻。介绍了该方法的实现原理,组建了应力波源定位实验系统。采用十字定位法确定发射源位置。结果表明,采用新的窄带特征提取技术后,定位误差从原来的15 mm减少到4.9 mm。
To enhance the measurement accuracy of time of arrival（TOA） of the stress wave, wavelet transform is used to extract the steady and clear narrow-band response from original wide-band non-stationary AE signals. Hilbert transform is further used to get the envelop of the narrow-band signals. The first peak of the envelop is taken as the arrival time of the stress wave. The new method can greatly remove the noise effect and the dispersion effect of stress wave, therefore a clear waveform can be acquired. A test system is setup to verify the effect of the proposed method. Results show the localization error of the simulated stress wave source is reduced from original 15 mm to 4.9 mm.
出处
《压电与声光》
CSCD
北大核心
2009年第2期292-295,共4页
Piezoelectrics & Acoustooptics
