Wavelet based harmonics decomposition of ultrasonic signal in assessment of plastic strain in aluminum
Wavelet based harmonics decomposition of ultrasonic signal in assessment of plastic strain in aluminum
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DOI：
10.1016/j.measurement.2017.04.013
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发表时间：
2017-08-01
期刊：
影响因子：
5.6
通讯作者：
Indacochea, J. Ernesto
中科院分区：
文献类型：
--
作者：
Mostavi, Amir;Kamali, Negar;Indacochea, J. Ernesto
在非线性超声学中，通过实验测量超声信号的一次和二次谐波幅度来计算声学非线性参数，从而研究微结构变化与超声特性之间的相关性。最流行的信号处理方法是将时域信号变换到频域，并从频谱中获取每个频率的幅度。然而，这种方法的主要缺点是，时间信息不被保存和变换误差显着增加，在分析非线性信号的不连续性。在这项研究中，两个基于小波的算法被引入到非线性超声检测的波形分析。将该算法应用于1100铝合金试件的非线性声学参数与塑性变形之间的关联，以验证其有效性。结果表明，该算法计算的声学非线性参数不受信号处理变量的影响，采用基于小波分解的方法可以减小信号处理误差。(C)2017爱思唯尔有限公司版权所有
In nonlinear ultrasonics, the correlation between microstructural change and ultrasonic properties is investigated by the acoustic nonlinearity parameter, calculated by experimentally measuring the first and second harmonic amplitudes of ultrasound signals. The most prevalent signal processing method is to transform the time-domain signal into the frequency domain and acquire the amplitudes of each frequency from the frequency spectrum. However, the major drawback of this approach is that temporal information is not preserved and the transformation errors increase dramatically in analyzing nonlinear signals with discontinuities. In this study, two wavelet-based algorithms are introduced to analyze the waveform in nonlinear ultrasonic testing. The algorithms are applied to correlate the acoustic nonlinearity parameter and the plastic deformation of aluminum 1100 specimens, for the purpose of validation. The results showed that the acoustic nonlinearity parameter calculated through the proposed algorithms is not influenced by the signal processing variables, and the signal processing error is reduced when the wavelet-based decomposition is applied. (C) 2017 Elsevier Ltd. All rights reserved.