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.

中文翻译：

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激光超声法定量评估单向碳纤维增强塑料中的孔隙度

摘要

提出并通过实验实现了一种基于测量其声阻抗的估算CFRP孔隙率的方法。测试样品的声阻抗来自于从浸没-液体-样品界面反射的超声波脉冲的反导幅度。所研究的样品是具有不同体积含量的基质和填料的单向CFRP。已经确定，样品中局部孔隙率的分布沿碳纤维堆叠平面是不均匀的。孔隙率的值在光学声学测量结果的平均值上加上测量误差，与X射线断层扫描数据一致。