Imaging Enhancement for Deep Concrete Blocks by
Wave-packet Decomposition and Amplitude
Publication: Publication Date: 1 May 2016Testing Method:
Nondestructive testing plays an important role in
the detection of discontinuities and degradation in
concrete structures. The synthesized aperture
focusing technique (SAFT) improves imaging
quality by superimposing the received signals from
adjacent transducers. However, in testing of deep
concrete blocks, the reflected ultrasonic signals
from targets usually combine with scattering, and
the amplitude of the useful signal decreases
rapidly with its propagation distance. It is hard for
traditional SAFT to give a clear display of the target
near the bottom. This paper proposes an
amplitude compensation technique to enhance the
reflected signals from deep targets, and a wavepacket
decomposition approach is used to identify
these reflections. The relative attenuation coefficient
of ultrasonic waves propagating in concrete
is obtained by measuring the decay in amplitude
of the first and second peaks of the processed
envelope signal. Experimental results in an artificial
concrete specimen (70 cm length × 60 cm
width × 60 cm height) show that the proposed
technique has higher imaging resolution than SAFT
and the traditional wave-packet decomposition
- Bigelow, T.A., “Estimating the Total Ultrasound Attenuation along the Propagation Path by Applying Multiple Filters to Backscattered Echoes from a Single Spherically Focused Source,” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 57, No. 4, 2010, pp. 900–907.
- Fink, M., F. Hottier, and J. Cardoso, “Ultrasonic Signal Processing for In Vivo Attenuation Measurement: Short Time Fourier Analysis,” Ultrasonic Imaging, Vol. 5, No. 2, 1983, pp. 117–135.
- Ganguli, A., C.M. Rappaport, D. Abramo, and S. Wadia-Fascetti, “Synthetic Aperture Imaging for Flaw Detection in a Concrete Medium,” NDT&E International, Vol. 45, No. 1, 2012, pp. 79–90.
- Kim, B.-C., and J.-Y. Kim, “Characterization of Ultrasonic Properties of Concrete,” Mechanics Research Communications, Vol. 36, No. 2, 2009, pp. 207–214.
- Mayer, K., R. Marklein, K. Langenberg, and T. Kreutter, “Three-dimensional Imaging System Based on Fourier Transform Synthetic Aperture Focusing Technique,” Ultrasonics, Vol. 28, No. 4, 1990, pp. 241–255.
- McCann, D., and M. Forde, “Review of NDT Methods in the Assessment of Concrete and Masonry Structures,” NDT&E International, Vol. 34, No. 2, 2001, pp. 71–84.
- Ophir, J., R. McWhirt, N. Maklad, and P. Jaeger, “A Narrowband Pulseecho Technique for In Vivo Ultrasonic Attenuation Estimation,” IEEE Transactions on Biomedical Engineering, Vol. 32, No. 3, 1985, pp. 205–212.
- Philippidis, T.P., and D.G. Aggelis, “Experimental Study of Wave Dispersion and Attenuation in Concrete,” Ultrasonics, Vol. 43, No. 7, 2005, pp. 584–595.
- Schickert, M., “Automated Ultrasonic Scanning System for Three-dimensional SAFT Imaging of Concrete Elements using an Electronically Switched Transducer Array,” 2012 IEEE International Ultrasonics Symposium, Dresden, Germany, 7–10 October 2012, pp. 40–43.
- Schickert, M., “Progress in Ultrasonic Imaging of Concrete,” Materials and Structures, Vol. 38, November 2005, pp. 807–815.
- Schmitz, V., S. Chakhlov, and W. Müller, “Experiences with Synthetic Aperture Focusing Technique in the Field,” Ultrasonics, Vol. 38, Nos. 1–8, 2000, pp. 731–738.
- Shao, Z., L. Shi, J. Cai, “Wavelet Modeling of Signals for Non-destructive Testing of Concretes,” Measurement Science and Technology, Vol. 22, March 2011.
199 Page Views
0 PDF Downloads
0 Facebook Shares