Abstract
A method for estimating the porosity of CFRPs based on measuring their acoustic impedances is proposed and experimentally implemented. The acoustic impedance of the test sample is derived from the magnitude of the antiderivative of an ultrasonic pulse reflected from the immersion-liquid–sample interface. The studied samples are unidirectional CFRPs with various volume contents of the matrix and filler. It has been established that the distribution of local porosity in the samples is uneven along the carbon fiber stacking plane. The value of porosity averaged over the results of optical–acoustic measurements with allowance for measurement errors is consistent with the X-ray tomography data. The method for estimating the value of porosity presented in this paper does not involve measuring the volume and mass of the object under study and can be used in diagnostics of complex shaped composite structures.
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Sokolovskaya, Y.G., Podymova, N.B. & Karabutov, A.A. Quantitative Evaluation of Porosity in Unidirectional CFRPs Using Laser Ultrasonic Method. Russ J Nondestruct Test 56, 201–208 (2020). https://doi.org/10.1134/S1061830920030109
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DOI: https://doi.org/10.1134/S1061830920030109