为了解决航空发动机原位裂纹的快速检测问题,通过数值模拟与实验分析相结合,分析激光超声透射波与不同深度缺陷的铝板相互作用后的频域波形峰值的变化.研究表明:(1)随着缺陷深度的增加,透射波频域波形的幅值整体上呈现降低的趋势;(2)由实验数据分析可得,缺陷深度从0.3 mm增加到0.9 mm时,Ⅰ、Ⅱ、Ⅲ区的峰值增加量分别为35.45%、24.90%、24.11%,即其增加量逐渐减小.该分析方法为超声信号表征表面微缺陷提供了一种思路,为今后从频域峰值方面分析裂纹深度奠定一定的基础.%In order to solve in situ the problem of rapid detection of cracks of aeroengine,the peak value of the frequency domain waveform after the interaction between the laser ultrasonic transmission wave and the aluminum plate with different depth has been analyzed by numerical simulation and experimental analysis. The results show that(1)with the increase of the depth of the defect,the amplitude of the transmitted wave frequency domain wave-forms tends to decrease as a whole;(2)from the experimental data analysis,when the defect depth increases from 0.3 mm to 0.9 mm,and the increase of peak in theⅠ,Ⅱ and Ⅲ regions was 35.45%,24.90% and 24.11%,respec-tively,and the increase was gradually decreased. This method provides a way to characterize the surface micro-defects of ultrasonic signals,which will lay a foundation for the future analysis of crack depth from the peak frequency.
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