碳纤维复合材料孔隙率超声衰减测试研究

探讨和分析了碳纤维复合材料孔隙率检测的各种方法以及理论方面的研究,指出材料内部孔隙形状与孔隙含量存在着相关性,孔隙含量超声衰减测量应考虑孔隙形貌因素,超声波频率因素对超声衰减孔隙含量测量存在着影响,不同频率超声波影响着超声衰减孔隙含量计算公式的具体形式,复合材料孔隙率检测的难点在于破坏性实验及孔隙特性不能与实测中超声信号充分点点对应,不能有效充分考虑孔隙特性,提出了一种基于孔隙特征的多分段拟合孔隙率超声衰减测试方法,并以一简单例子对多分段拟合结果进行了分析.

Porosity test in carbon composites based on a new ultrasonic attenuation method

The theory and empirical equations of porosity test in carbon composites are discussed in this article. The void shape and size is correlated with the void content. The void morphology and content should be taken into account in porosity test by ultrasonic attenuation method. The ultrasonic frequency has an effect on porosity test, and the constant of the equation is correlated with the frequency. A new porosity -based uhrasonic attenuation test method is proposed. In the new method a professional data base of different kinds of material, different ultrasonic frequencies and different range of porosity content need to be established. Multi - segment fit method is used in the empirical equations accounting for the void content and shape factor. A simple example shows the porosity -based ultrasonic attenuation method can improve the porosity calculation accuracy.