Title:
Wavelet Analysis of Ultrasonic Pulses in Cement-Based Materials
Author(s):
Carnot Leal Nogueira
Publication:
Materials Journal
Volume:
107
Issue:
3
Appears on pages(s):
248-257
Keywords:
attenuation; cement-based materials; frequency analysis; grain-size distribution; nondestructive testing; phase velocity; ultrasonic testing; wavelets
DOI:
10.14359/51663753
Date:
5/1/2010
Abstract:
A novel technique based on wavelet time-frequency decomposition was applied in the analysis of ultrasonic pulses. With the method, frequency-dependent attenuation and velocity can be calculated for both longitudinal and shear waves. A total of 14 specimens with five different mixture proportions were scrutinized and the results demonstrated the viability of a high frequency ultrasound (above 100 kHz) to analyze cement-based materials. The technique applied the continuous wavelet transform and had advantages when compared to any Fourier-based method. A method to analyze grain-size distribution based on the properties of the Rayleigh, stochastic, and diffuse attenuation regions was also presented. The procedure relied on the wavelet calculation of frequency dependent attenuation and yielded estimates of aggregate proportions. The capability of extracting frequency-dependent parameters via wavelet transform can be used for any nondestructive testing method based on wave propagation, such as impact-echo or acoustic emission.