基于频域参量的石英复合材料孔隙超声表征方法研究

孔隙率对复合材料性能有很大影响。针对高孔隙率复合材料超声表征不足问题,本文把超声功率谱特征和非线性特征应用于表征高孔隙石英酚醛复合材料的孔隙率,即在频域上对比研究孔隙对基波幅值的衰减及谐波幅值的滋生的影响。结果表明:二者均能有效表征高孔隙复合材料的孔隙率。基于频域基波分析的超声功率谱特征参量测量容易,随孔隙增加呈递减变化,在孔隙率较低时具有一定优势;基于谐波分析的超声二阶非线性特征参量,随孔隙增加呈递增变化,对高孔隙率表征更具优势。

Characterization of Porosity in Quartz Composites Based on Ultrasonic Frequency Domain Parameters

The porosity had a great influence on the properties of the composites. To solve the problem that ultrasound could not well characterize high porosity composite materials,the characteristics and nonlinear characteristics of ultrasonic power spectrum were applied to characterize porosity of high porosity quartz phenolic composites, which is the effect of pores on the attenuation of fundamental amplitude and the breeding of harmonic amplitude in frequency domain. The results show that both methods can effectively characterize the pore content of high porosity composites. It is easy to measure the ultrasonic power spectral characteristic parameters based on the fundamental analysis in frequency domain, and it decreases with the increase of pore, which has some advantages when the porosity is low. The second order nonlinear characteristic parameters of the ultrasonic wave based on harmonic analysis are increasing with the increase of porosity, which is more advantageous to the high porosity characterization.