Application of Prestack Migration Theory in Flaw Detection of Concrete Structure
Application of Prestack Migration Theory in Flaw Detection of Concrete Structure
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发表时间：
2010
影响因子：
26.6
通讯作者：
Ying Luo;Zhongfang Li
中科院分区：
文献类型：
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作者：
Ying Luo;Zhongfang Li
介绍了一种基于叠前偏移的混凝土结构剖面超声成像实验。反射波被用于通过叠前偏移进行剖面成像，从而允许人们仅从结构的一侧检测任意角度的缺陷。通过理论和实证分析了影响偏移剖面精度误差的因素，并将偏移方法的结果与另一种方法的结果进行了比较，得出两个结论：第一，如果滤光片的主频与实际回波的主频一致，换能器间距小于反射主波长的四分之一，偏移速度不低于物理波速，则可以得到分辨率较高的偏移剖面。其次，如果迁移速度远大于物理迁移速度，则检测结果会更深。叠前偏移比水平叠加法精度更高，对倾斜界面的适应能力更强。
An experiment about ultrasonic imaging of concrete structure profile based on prestack migration is presented. Reflected waves are used for profile imaging by prestack migration, so that permit one to detect flaws of arbitrary angles from only one side of the structures. By theoretical and empirical analyzing the in- fluencing factors about the accuracy errors of the migration sections, comparing the results with the migration method to that of the other method, we drew out two conclusions: Firstly, we can get the migration section with high resolution if the main frequency of the filter is accord with that of the real echo , the space between transducers is smaller than one quarter of the reflecting main wavelength, the migration speed is no less than the physical wave speed. Secondly, the detection result would be deeper if the migration speed is much larger than the physical one. Lastly, the prestack migration gives higher precision and possesses more adaptability to the inclining interface of the damages than the horizontal stack method.