中文摘要：

根据超声波透射法检测原理，在一定的假设基础上，针对层数不同的层板碳纤维复合材料，建立了孔隙率与材料层数、超声衰减量的关系模型，利用5组不同层数样本试块的孔隙率和超声衰减量的试验数据，给出了基于模型的孔隙率拟合公式。分析和试验结果表明，拟合公式具有一定的精度，满足工程检测的要求。该模型可用于检测同批次下不同层数复合材料的孔隙率，且不需要制备大量的试验样本，既方便快捷又节约成本。在此基础上，对模型进行了修正，建立了变厚度层板复合材料孔隙率与材料厚度、超声衰减的关系模型，并对模型进行了讨论，该模型适合于大曲率半径结构件。

英文摘要：

Based on the principle of ultrasonic transmission method with some hypothesis, a relationship model between porosity, the number of layers and the ultrasonic attenuation was established for different CFRP laminates. Firstly, under several assumed conditions, a relationship model between the number of layers and the ultrasonic attenuation was established without porosity. This model can reflect effect of other factors on the ultrasonic attenuation. Then, considering the effect of voids, the model was improved with the factor of porosity. Finally, using the test data of the porosity and ultrasonic attenuation for 5 different laminate test blocks, a fitting porosity mode was given. The analysis and test result show the model has enough precision and can certify the requirement of＇~ngineering test. This model can be used to test the porosity of different composite laminates in same bath and doesn＇t need to prepare too many samples, so it is convenient and fast, as well as cost saving. On the basis, a relationship model between porosity, thickness and ultrasonic attenuation was established by revising the porosity model. As for composites with variable thickness, it is needed to replace the number of layers by thickness. What＇s more, refraction phenomenon may occur while the ultrasound propagates at the back wall. So other factors should be revised. The analysis shows that, the included angle between the propagation direction and the normal direction of back wall plays an important part in the model. And the attention will increase rapidly with the angle increases. So the model is suitable for the composites with big curvature radiuses.