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| 基于弯曲路径的混凝土超声层析成像及其改进 | |
| 引用本文： | 熊炜,周曾辉,余开彪,吴亚平,罗炜.基于弯曲路径的混凝土超声层析成像及其改进[J].岩土力学,2011,32(2):629-634. |
| 作者姓名： | 熊炜 周曾辉 余开彪 吴亚平 罗炜 |
| 作者单位： | 1. 中国科学院武汉岩土力学研究所,武汉430071;中国科学院成都光电研究所,成都,610209 2. 中国科学院武汉岩土力学研究所,武汉,430071 3. 武汉软件工程职业学院,武汉,430205 |
| 摘 要： | 针对混凝土质量检测的特点,采用弯曲射线进行超声层析成像。首先建立波速分布的网格模型,并引入最短路径法进行射线追踪,然后采用联合迭代重建技术(SIRT)反演成像。为使算法适应弯曲射线,对SIRT的计算步骤进行调整,增加外层迭代,以便对修正后的路径进行下一轮反演;为提高反演精度,根据射线传播距离、幅度衰减、频率突变等信息建立和调整信号可信度系数,并依据该系数在求取网格慢度修正值时进行加权平均;为缩短计算时间,动态调整网格节点个数,并进行双向最短路径追踪。经过数值模拟及对混凝土基桩的实测,证明该方法在计算准确性和精度上有明显改进,计算速度也可以满足工程应用的需要。 |
| 关 键 词： | 混凝土 弯曲射线 最短路径 联合迭代 层析成像 |
| 收稿时间： | 2009-01-23 |
Concrete ultrasonic tomography imaging and improvement based on curved path |
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| XIONG Wei,ZHOU Zeng-hui,YU Kai-biao,WU Ya-ping,LUO Wei.Concrete ultrasonic tomography imaging and improvement based on curved path[J].Rock and Soil Mechanics,2011,32(2):629-634. | |
| Authors: | XIONG Wei ZHOU Zeng-hui YU Kai-biao WU Ya-ping LUO Wei |
| Institution: | 1. Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; 2. Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China; 3. Wuhan Vocational College of Software Engineering, Wuhan 430205, China |
| Abstract: | Because of the characteristic of concrete quality detection, it’s necessary to adopt the bending ray in the technique of ultrasonic tomography. A grid model of wave speed distribution is built at first. Then the ultrasonic ray is traced with the shortest path method and the simultaneous iterative reconstruction technique(SIRT) is adopted to image. In order to adjust the algorithm to bending ray, the calculation procedure of SIRT is revised. The iteration in the outer layer is enhanced to do the next inversion of the modified path. To improve the inversion precision, the signal reliability coefficient is established and revised according to the informations such as: ray propagation distance, amplitude attenuation and frequency break, etc. According to this coefficient, the weighted average is calculated when solving the modified value of grid slowness. In order to improve the calculation speed, the grid number is dynamically adjusted; and the shortest path is searched in bi-direction. Through the numerical simulation and field measurement of concrete piles, it is proved that there is an obvious improvement on the calculation accuracy; and its calculation speed can be accepted in the engineering application. |
| Keywords: | concrete bending ray shortest path simultaneous iterative reconstruction technique ultrasonic tomography |
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