Ultrasound SAFT imaging for HSR ballastless track using the multi-layer sound velocity model
Ultrasound SAFT imaging for HSR ballastless track using the multi-layer sound velocity model
复制标题
使用多层声速模型对 HSR 无碴轨道进行超声 SAFT 成像
DOI：
10.1784/insi.2021.63.4.199
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发表时间：
2021-04
期刊：
影响因子：
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通讯作者：
Han-Fei Zhang
中科院分区：
文献类型：
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作者：
Wen-Fa Zhu;Guo-Peng Fan;Xiang-Zhen Meng;Yao Cheng;Hai-Yan Zhang;Li-Ming Li;Wei Shao;Xing-Jie Chen;Han-Fei Zhang
准确检测无砟轨道结构中的空洞缺陷，已成为我国高速铁路线路结构养护维修亟待解决的核心问题。本研究通过结合均方根速度法与合成孔径聚焦技术（SAFT）超声成像，提出了适用于多层结构空洞缺陷检测的均方根合成孔径聚焦技术（RMS - SAFT）超声成像方法。首先，建立高速铁路无砟轨道的多层声速模型（声音传播时间与传播距离之间的关系模型），将声音传播时间表示为以声速均方根为自变量的函数。其次，依据多层声速模型计算声波在高速铁路无砟轨道中的传播时间，并将所得传播时间代入SAFT超声成像方法进行成像。最后，通过有限元模拟和试验对该方法的准确性进行验证。结果表明，对于各层声速差异极小的高速铁路无砟轨道，多层声波模型计算出的声音传播时间具有较高精度。所提出的RMS - SAFT超声成像方法提高了传统SAFT成像的精度，实现了高速铁路无砟轨道空洞缺陷的精确成像。
Accurate detection of void defects in ballastless track structures has become a core problem that needs urgent resolution for the maintenance and repair of high-speed railway (HSR) line structures in China. In this study, the root mean squaresynthetic aperture focusing technique (RMS-SAFT). ultrasound imaging method, which is suitable for the void defects of multi-layer structures, is proposed by combining the RMS velocity method and SAFT ultrasound imaging. First, a multi-layer sound velocity model (the relationship model between sound propagation time and sound propagation. distance) of the HSR ballastless track is established. The sound propagation time is expressed as a function of the RMS of sound propagation speed as an independent variable. Second, the propagation time of the sound wave in the HSR ballastless track is calculated in accordance with the multi-layer. sound velocity model and the obtained propagation time is substituted into the SAFT ultrasound imaging method for imaging. Lastly, the accuracy of the method is verified through a finite element simulation and an experiment. The results show that for the HSR ballastless track with minimal. differences in the sound propagation speed at each layer, the sound propagation time calculated by the multi-layer sound wave model has high accuracy. The proposed RMS-SAFT ultrasound imaging method improves the accuracy of traditional SAFT imaging and realises accurate imaging of the void. defects of HSR ballastless track.