作者：蒋剑, 郑慧峰, 王月兵, 赵鹏, 沈超

作者单位：中国计量大学计量测试工程学院, 浙江 杭州 310018

关键词：声学;内部缺陷检测;超声CT;缺陷定位

摘要：

为实现水下桥墩体内缺陷的检测与定位，提出一种将超声CT技术与质心定位技术相结合的方法。采用环形换能器阵列对桥墩截面以扇形束的扫描方式获取投影数据，使用滤波反投影算法重建截面的灰度图像，以实现内部缺陷的检测。鉴于声波在传播过程中会发生反射、折射等现象，利用区域生长算法分割出图像中的缺陷区域，进而求解出该区域灰度图的质心作为缺陷的位置点。计算机仿真结果表明，该方法能够重建较高质量的截面图像，并且能够快速识别体内缺陷所处位置。搭建检测系统对水下混凝土样块进行实验，较好地重建出样块中的缺陷，计算出缺陷定位的相对误差为4.6%，表明该方法切实可行并具有很好的实用性。

Research on the method of internal defects detecting and locating for underwater bridge pier

JIANG Jian, ZHENG Huifeng, WANG Yuebing, ZHAO Peng, SHEN Chao

College of Metrology & Measurement Engineering, China Jiliang University, Hangzhou 310018, China

Abstract: In order to realize the detection and localization of internal defects of underwater bridge piers, a method combining centroid localization technology with ultrasonic CT technology was proposed. An annular transducer array was used to acquire the projection data of the pier section by fan-beam scanning mode. The filter-back projection algorithm was used to reconstruct the grayscale image of the section to realize the detection of internal defects. Considering the reflection, refraction and other phenomenon in the propagation of acoustic wave, the region growing algorithm was used to segment the defect area in the image, and then the location of the defect was determined through calculating the centroid of the grayscale image in the defect area. Computer simulation results demonstrated that this method can reconstruct a high quality cross-section image and identify the location of the internal defect efficiently. A detection system was set up to test a concrete sample in the water and the results showed that the defect in the sample block was reconstructed well. The relative error of the defect location was calculated to be 4.6%, which proved that the method is feasible and practical.

Keywords: acoustics;internal defect detection;ultrasonic CT;defect localization

2018, 44(9): 29-34  收稿日期: 2018-04-22;收到修改稿日期: 2018-05-18

基金项目: 国家重点研发项目（2017YFF0205004）；国家自然科学基金（11474259）；浙江省“仪器科学与技术”重中之重学科人才培育项目（JL150506）；浙江省大学生科研创新活动计划项目（2018R409035）

作者简介: 蒋剑(1994-),男,安徽六安市人,硕士研究生,专业方向为仪器仪表工程

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