碳纤维复合材料分布孔隙率的超声衰减检测方法

ULTRASONIC ATTENUATION TESTING METHOD FOR NDE OF VOID CONTENT BASED ON THEORETICAL MODEL AND EXPERIMENT CALIBRATION

文中提出一种基于理论建模与实验标定的碳纤维复合材料孔隙率超声衰减检测方法。此方法对包含超声波频率、树脂、碳纤维、按尺寸分布孔隙等的多种衰减影响作用在内的理论模型进行分析简化，而建立起检测模型，较好地解决了前人的理论模型与检测结果不一致问题，并使其方法本身具有适用意义。对相应导出的检测关系式通过破坏性实验标定，保证了本方法检测结果的可靠性。给出了一种标定检测关系式的实验方法，并对其精度进行了分析。通过实验分析，对所提出的方法进行了示例性实现。

A new method is proposed for non destructive evaluation (NDE) of void content of carbon fibre reinforced plastics. The method establishes a testing model which is based on a theoretical model and calibrated by experiment. Thus the problem of the disagreement between present models and experiment results is well solved. Under reasonable simplifying conditions, the detection relationship between ultrasonic attenuation and void content established is simple for practice. The unifying form of the relationship has general meanings and the application formula calibrated by experiment is just fit to given materials. Attention is paid in this paper both to the conformability and reliability of the method. In this model the effects to the ultrasonic attenuation of the ultrasonic frequency, the content and sizes of voids and fibres, the content of resink and other flaws are considered. The theoretical calculation results are compared with some experiment data and it shows that they are considerably matching. The simplifying conditions are discussed in detail and the method for determining the coefficients of the application relationship formulas is presented. At last, an example to illustrate the implementation and realization of the method and the relative experiment results are given.