Fundamental study on ultrasonic measurement system to detect penetration of boulders using cepstrum analysis

• Published in: Ultrasonics Vol. 46; no. 3; pp. 266 - 269
• Main Authors: Kawamura, Y., Tsurushima, M., Ito, Y., Mizutani, K., Yamachika, S., Aoshima, N., Ha, E.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2007; Elsevier Science
• Subjects: Acoustical measurements and instrumentation; Acoustics; Applied sciences; Auto correlation analysis; Building structure; Buildings. Public works; Cepstrum analysis; Concrete structure; Construction (buildings and works); Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Engineering geology; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Physics; Solid mechanics; Structural and continuum mechanics; Ultrasonic wave; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Ultrasonic wave; Auto correlation analysis; AE; Cepstrum analysis; Acoustic measurement; Vibration; boulders; Elastic wave; Experimental study; Spectral analysis; Wave reflection; Wide band signal; Data acquisition system; Domain structure; Correlation analysis; Cepstrum; Ultrasonic control; Concrete construction; Elastic shock; Concrete; Elastodynamics; Non destructive test; Ultrasound; Impact test
• ISSN: 0041-624X; 1874-9968
• DOI: 10.1016/j.ultras.2007.03.001

Generally, ultrasonic method and an elastic impact wave method are mentioned as examples representing the nondestructive test method. However, the ultrasonic method is known for the investigation of shallow depth becoming very shallow because of its small input. And the elastic impact wave method uses for example, a hammer for the discrimination of the reflection wave produced by minute cracks existing in the object, which is difficult. Theoretically, if it becomes possible to input the vibration of an ultrasonic domain into artificial structures such as a concrete and a boulder with strong amplitude, deeper investigation of depth and higher precision will be attained. The authors have developed a new ultrasonic method by using ultrasonic wave of the chirp signal, using the input of this system and using auto correlation and cepstrum as the analysis methods. In this paper, the experiment is classified into Pattern 1 and Pattern 2. In Pattern 1, the experiment of receiving the reflection wave was carried out using the concrete block with a width of 1300 mm and the down chirp signal from 50 kHz to 40 kHz. In Pattern 1, a reflection wave was clearly detected, and the length of the concrete block was calculated using auto correlation analysis, and was obtained as 1311.76 mm. In Pattern 2, the experiment of receiving the reflection wave was carried out using the same concrete block and the down chirp signal from 150 kHz to 130 kHz. In Pattern 2, the direct wave and the reflection wave were mixed, therefore it was not possible to presume the length from the obtained waveform. So cepstrum analysis method was used, and the traveling time of the reflection wave was obtained. In this result, the length of the concrete block was given as 1278.25 mm.