基于幅度补偿的混凝土合成孔径聚焦成像方法

发布时间：2018-04-29 21:50

  本文选题：无损检测 + 混凝土　； 参考：《南京航空航天大学学报》2017年04期

【摘要】：合成孔径聚焦技术(Synthetic aperture focusing technique,SAFT)通过叠加邻近多道通的回波信息,可增强目标缺陷的信号特征,被广泛应用于超声无损检测领域。对于大深度混凝土结构的无损检测问题,由于超声波的衰减作用明显,传统B扫描及SAFT方法的成像效果均不理想。为提高混凝土超声成像的质量,测定了混凝土中超声波传播的相对衰减系数,引入幅度补偿技术对微弱回波信号进行幅度补偿,然后再对补偿信号进行SAFT成像处理,进一步增强了超声成像效果。人工混凝土块实验表明,本文所提方法比传统成像方法具有更高的成像分辨率,底部缺陷反射更加清晰,同时内嵌铁管及木块的实验均验证了本文方法的有效性。
[Abstract]:Synthetic aperture focusing technique (SAFTFT) can enhance the signal characteristics of target defects by superimposing the echo information of adjacent multichannel, and is widely used in the field of ultrasonic nondestructive testing (NDT). For the problem of nondestructive testing of concrete structures with large depth, the traditional B-scan and SAFT imaging methods are not satisfactory because of the obvious attenuation of ultrasonic wave. In order to improve the quality of ultrasonic imaging of concrete, the relative attenuation coefficient of ultrasonic propagation in concrete is measured. Amplitude compensation technique is introduced to compensate the weak echo signal, and then the compensation signal is processed by SAFT imaging. The ultrasonic imaging effect is further enhanced. The experiments of artificial concrete block show that the method proposed in this paper has higher imaging resolution and clearer reflection of defects in the bottom than the traditional imaging method, and the effectiveness of the proposed method is verified by the experiments of inlay iron pipe and wood block.
【作者单位】： 解放军理工大学电磁环境效应及光电工程国家级重点实验室;
【基金】：国家自然科学基金(51407198,10872217)资助项目
【分类号】：TU528.07
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本文编号：1821725