Detection and localization of microcracking in polymer concrete using coda wave interferometry (CWI) at resonance

• Published in: The Journal of the Acoustical Society of America Vol. 138; no. 3_Supplement; p. 1836
• Main Authors: Mechri, Charfeddine, Bentahar, Mourad, Toumi, Souad, Boubneider, Fouad, El Guerjouma, Rachid
• Format: Journal Article
• Language: English
• Published: 01-09-2015
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4933841

Nonlinear resonance and Coda Wave Interferometry (CWI) proved their potential to detect the evolution of a structure, namely, in the case of damage. Nevertheless, these techniques do not allow localizing defects in a structure. CWI may allow this localization through heavy statistical algorithms. In this case, the main problem remains the real time monitoring on one hand. On the other hand, in the case of highly scattering media, the amplitude of the acoustic pulse may cause the Coda signal to be affected by conditioning/relaxation effects. Moreover, Coda signal is very sensitive to experimental conditions, namely, to temperature. In order to overcome these inconveniences, we propose a method based on a comparative study of Coda signal contents in rest state and under a weak (linear) vibration. In this communication, we report the results obtained on a polymer concrete specimen excited under different resonance modes and for different dispositions of the sample which defect is not isotropic on which we apply simultaneously through transmission experiments in order to monitor changes in the coda signal.