基于合成孔径聚焦成像技术的混凝土缺陷检测实验分析

Experimental analysis of concrete defect detection based on synthetic aperture focusing technology

为研究合成孔径聚焦成像技术在混凝土缺陷识别中的应用,先后采用常规的超声脉冲法(探头频率50 kHz)与合成孔径聚焦成像法(探头频率50 kHz,32阵元)对预制缺陷的混凝土试块进行检测对比,分析混凝土内部预制缺陷在两种超声检测方法中的成像特征。研究结果表明,传统的超声检测方法无法准确判断出混凝土内部结构缺陷,且对缺陷尺寸信息的获取较少。采用合成孔径聚焦成像法获得混凝土内部结构的二维B扫图像可以准确识别出50 mm深度以下,缺陷横向直径为40 mm,纵向厚度为3 mm的空洞缺陷,并能够准确读取该缺陷在混凝土试块中的相对位置信息,从而达到定量分析的目的。

In order to study the application of synthetic aperture focusing imaging technology in the identification of concrete defects,conventional ultrasonic pulse method(probe frequency 50 kHz)and synthetic aperture focusing imaging method(probe frequency 50 kHz,32 elements)were used to carry out precast defects on concrete test blocks.Inspection and comparison,analysis of the imaging characteristics of concrete internal precast defects in two ultrasonic inspection methods.The research results show that the traditional ultrasonic inspection method cannot accurately determine the internal structural defects of concrete,and the information on the size of the defects is less obtained.Using synthetic aperture focusing imaging method to obtain two-dimensional B-scan images of concrete internal structure can accurately identify void defects with a depth of less than 50 mm,a defect with a transverse diameter of 40 mm and a longitudinal thickness of 3 mm,and can accurately read the relative position information of the defect in thde concrete block,so as to achieve the purpose of quantitative analysis.