500
X. Zeng et al.
As a kind of AE detection tool at elevated temperature, the rod waveguide can be
used to get clear signal when the concerned frequency is less than a certain threshold.
According to the Figs. 43.2 and 43.3, when the frequency of the signal is less than
300 kHz, there are less modes. Besides, the attenuation of energy is smaller. In view
of the above reasons, for the rod waveguide made of 304 stainless steel, the threshold
is about 300 kHz.
43.6 Conclusion
According to this study, the following conclusions can be drawn:
1. The influence of the rod waveguide on the AE signal comes from two aspects:
the rod waveguide and the interface between the rod waveguide and specimen.
In these factors, the rod waveguide attenuates the energy and amplitude of
the acoustic signal. Besides, the attenuation degree increases with the rise of
frequency. However, the energy and amplitude will increase after the wave goes
into the waveguide with higher wave impedance. In addition, the variations of
frequency are small.
2. When a rod waveguide is used in AE detection, the clustering method based on
energy and amplitude is not accurate and the peak frequency is a good choice.
3. The rod waveguide can be used in AE detection when the concerned frequency
of wave is less than certain threshold. For different materials, the thresholds may
be different.
Acknowledgement The study is supported by the 111 Project, No. BP0719007.
References
1. A.M. Zelenyak, M.A. Hamstad, M. Sause, Modeling of acoustic emission signal propagation
in waveguides. Sensors-Basel 15(5), 11805–11822 (2015)
2. J. Sikorska, J. Pan, The effect of waveguide material and shape on acoustic emission
transmission characteristics. J. Acoust. Emission 22, 264–273 (2004)
3. T.L. Szabo, Time domain wave equations for lossy media obeying a frequency power law. J.
Acoust. Soc. Am. 96(1), 491–500 (1994)
4. W. Cai, W. Chen, Fractional derivative modeling of frequency-dependent dissipative mechanism for wave propagation in complex media. Chin. J. Theor. Appl. Mech. 48(6), 1265–1280
(2016)
5. T.L. Szabo, J. Wu, A model for longitudinal and shear wave propagation in viscoelastic media.
J. Acoust. Soc. Am. 107(5), 2437 (2000). (Pt 1)
6. Z. Lu, N. Zou, S. Li, Y. Liu, Z. Liu and S. Jin, “Analysis of modes and dispersion for ultrasonic
guided wave detection in pipes,” Nondestructive Test, 2016.
7. M.G. Silk, K.F. Bainton, The propagation in metal tubing of ultrasonic wave modes equivalent
to Lamb waves. Ultrasonics 17(1), 11–19 (1979)
X. Zeng et al.
As a kind of AE detection tool at elevated temperature, the rod waveguide can be
used to get clear signal when the concerned frequency is less than a certain threshold.
According to the Figs. 43.2 and 43.3, when the frequency of the signal is less than
300 kHz, there are less modes. Besides, the attenuation of energy is smaller. In view
of the above reasons, for the rod waveguide made of 304 stainless steel, the threshold
is about 300 kHz.
43.6 Conclusion
According to this study, the following conclusions can be drawn:
1. The influence of the rod waveguide on the AE signal comes from two aspects:
the rod waveguide and the interface between the rod waveguide and specimen.
In these factors, the rod waveguide attenuates the energy and amplitude of
the acoustic signal. Besides, the attenuation degree increases with the rise of
frequency. However, the energy and amplitude will increase after the wave goes
into the waveguide with higher wave impedance. In addition, the variations of
frequency are small.
2. When a rod waveguide is used in AE detection, the clustering method based on
energy and amplitude is not accurate and the peak frequency is a good choice.
3. The rod waveguide can be used in AE detection when the concerned frequency
of wave is less than certain threshold. For different materials, the thresholds may
be different.
Acknowledgement The study is supported by the 111 Project, No. BP0719007.
References
1. A.M. Zelenyak, M.A. Hamstad, M. Sause, Modeling of acoustic emission signal propagation
in waveguides. Sensors-Basel 15(5), 11805–11822 (2015)
2. J. Sikorska, J. Pan, The effect of waveguide material and shape on acoustic emission
transmission characteristics. J. Acoust. Emission 22, 264–273 (2004)
3. T.L. Szabo, Time domain wave equations for lossy media obeying a frequency power law. J.
Acoust. Soc. Am. 96(1), 491–500 (1994)
4. W. Cai, W. Chen, Fractional derivative modeling of frequency-dependent dissipative mechanism for wave propagation in complex media. Chin. J. Theor. Appl. Mech. 48(6), 1265–1280
(2016)
5. T.L. Szabo, J. Wu, A model for longitudinal and shear wave propagation in viscoelastic media.
J. Acoust. Soc. Am. 107(5), 2437 (2000). (Pt 1)
6. Z. Lu, N. Zou, S. Li, Y. Liu, Z. Liu and S. Jin, “Analysis of modes and dispersion for ultrasonic
guided wave detection in pipes,” Nondestructive Test, 2016.
7. M.G. Silk, K.F. Bainton, The propagation in metal tubing of ultrasonic wave modes equivalent
to Lamb waves. Ultrasonics 17(1), 11–19 (1979)