Journal Published Online: 25 March 2019
Volume 48, Issue 2

Estimation of Wave Velocity for Ultrasonic Imaging of Concrete Structures Based on Dispersion Analysis

CODEN: JTEVAB

Abstract

Wave velocity is the most critical parameter used by the synthetic aperture focusing technique for the ultrasonic imaging of concrete structures. However, it has been challenging to estimate wave velocity with the traditional time-domain method that requires the picking of direct waves. The dispersion trend of direct waves is theoretically a horizontal line with frequency as the x-axis and phase velocity as the y-axis, and the horizontal line is due to the nondispersive phenomenon of direct waves in an elastic, homogeneous material. To overcome the challenge of picking direct waves in the time domain, this study proposes a frequency-domain method to first obtain the dispersion trend of direct waves based on the nondispersive phenomenon and then estimate the shear-wave velocity from the average phase velocity of the nondispersive trend in the frequency domain. This frequency-domain method was verified with the numerical and experimental ultrasonic data from concrete specimens with embedded delamination. A comparison of the results obtained using the two methods indicates that the frequency-domain method can significantly improve the accuracy of estimating the shear-wave velocity and eventually improve the accuracy of ultrasonic imaging.

Author Information

Lin, Shibin
School of Civil Engineering, Dalian University of Technology, Dalian, China
Shams, Sadegh
Turner-Fairbank Highway Research Center, Federal Highway Administration, VA, USA
Choi, Hajin
Department of Architectural Engineering, Soongsil University, Seoul, Republic of Korea
Meng, Dewei
Turner-Fairbank Highway Research Center, Federal Highway Administration, 6300 Georgetown Pike, McLean, VA, USA
Azari, Hoda
Turner-Fairbank Highway Research Center, Federal Highway Administration, VA, USA
Pages: 13
Price: $25.00
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Details
Stock #: JTE20180343
ISSN: 0090-3973
DOI: 10.1520/JTE20180343