用信号分析技术检测材料的声速和衰减

Measurements of Material's Acoustic Velocity and Attenuation by Signal Analysis

用快速傅氏变换 (FFT)技术进行超声回波信号分析 ,以回波传递函数导出与声速和衰减有关的频域方程 ;用频谱比方法测量材料的衰减品质因素Q值 ,并与脉冲法所得结果进行比较 .

In this paper, the frequency domain equations were deduced from the echo transfer function by the analysis of echo signals with fast Fourier transform (FFT) technology. The material's quality attenuation value Q were measured with frequency spectrum ratio method. Experiment methods, related instruments were also introduced. Examples of measurements were given and the results were compared with those of pulse method.