基于衍射波的孔类缺陷超声相控阵定量方法研究

The quantitative method of hole-type defects with diffracted echo by phased array ultrasonic technology

针对常规超声检测方法对小孔型缺陷难以准确定量的问题,利用超声相控阵的声束偏转聚焦和成像技术,基于固体中横孔对声波的衍射特性,提出采用一次反射回波和衍射回波来确定孔类缺陷的直径尺寸。首先,利用动态光弹系统对声波入射横孔的传播规律进行研究,分辨出一次反射回波与衍射回波。其次,采用超声相控阵系统对不同深度下孔径分别为φ1 mm、φ2 mm、φ3 mm、φ4 mm以及同一深度下孔径差值为0.2 mm的等差横孔进行定量实验。研究结果表明利用本文提出的定量方法能快速有效的确定孔型缺陷直径尺寸,对相控阵的定量问题研究具有一定的参考价值。

For conventional ultrasonic testing of small hole defect accurate quantitative problems, it comes up with a new method by the ultrasonic phased array beam focusing and imaging technology, based on the diffraction characteristics of acoustic wave in a solid, a reflection echo of cross-drilled hole and diffracted echo are proposed to determine the size of the cross-drilled hole. Firstly, the acoustic propagation law of cross- drilled hole in an optical glass was observed by a photoelastic system. A reflection echoes and diffraction were distinguished clearly. And then, the aperture respectively under different depth ~1 mm, ~2 mm, 63 mm, ~4 mm and the same depth of pore size difference is 0.2 mm cross-drilled hole was tested by phased array ultrasonic system. The results show that the quantitative method proposed in this paper can quickly and efficiently determine the size of defects, which indicates that the idea provides a reference for the quantification study of phased array.