基于小波包能量变化率的激光超声处理

发布时间：2018-05-31 09:18

本文选题：激光超声 + 小波包分解　；参考：《中国测试》2017年11期

【摘要】：为提供解决航空发动机原位裂纹的快速检测方法,得到缺陷深度与特征量之间的关系,使用激光器在一系列不同缺陷深度的航空板上激发声表面波,对收集到的信号进行预处理,并提出新的小波包变换能量变化率指标,用于进行缺陷损伤识别。结果表明:反射波信号在S_(80)、S_(81)频带上的小波包能量变化率随缺陷深度的增加呈现增加趋势,增长幅度分别为96.8%、86.3%;而反射回波在S_(80)、S_(83)频带上的小波包能量变化率较为显著,增长幅度分别为23.8%、80.2%。该分析方法为激光超声表征表面缺陷提供新的思路,为今后从能量变化率指标分析裂纹深度奠定基础。
[Abstract]:In order to provide a fast detection method for in-situ cracks in aeroengine and to obtain the relationship between defect depth and characteristic quantity, a laser is used to excite saw on a series of aeronautical plates with different defect depths. The collected signals are preprocessed and a new index of energy change rate of wavelet packet transform is proposed for defect damage identification. The results show that the change rate of wavelet packet energy of the reflected wave signal in the SSP / S / S / S _ 1) frequency band increases with the increase of the depth of the defect, and the amplitude of the increase is 96.8and 86.3respectively, while the rate of energy change of the reflected wave signal is more obvious in the frequency band of S _ S _ T _ 80 / S _ T _ (83). The growth ranges were 23.80.2and 80.2respectively. This analysis method provides a new idea for laser ultrasonic characterization of surface defects and lays a foundation for the analysis of crack depth from the energy change rate index in the future.
【作者单位】：中北大学计算机与控制工程学院;中北大学电子测试技术重点实验室;
【分类号】：TB559;V263.6

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