Numerical and Experimental Research on Identifying a Delamination in Ballastless Slab Track
Numerical and Experimental Research on Identifying a Delamination in Ballastless Slab Track
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无砟板轨道分层识别的数值与实验研究
DOI：
10.3390/ma12111788
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发表时间：
2019-06-01
期刊：
影响因子：
3.4
通讯作者：
Chai, Xiaodong
中科院分区：
文献类型：
--
作者：
Fan, Guopeng;Zhang, Haiyan;Chai, Xiaodong
采用全聚焦法和波数法对板式无碴轨道分层进行表征。12个干点接触（DPC）传感器位于板轨道的上表面组成一个线性阵列。这些传感器被用来激励剪切波，这是适合于识别分层。为了只保留分层引起的散射波和底板底部的反射波，采用了去除表面波的技术。数值和实验结果表明，所提出的方法可以识别出底板的脱层和底板。此外，去除表面波后，近地表的赝象现象得到了明显的抑制。与TFM相比，波数法在提高计算性能和横向分辨率方面具有很大的优势。然而，它们在纵向分辨率上没有显著差异。此外，它已被证实，横向分辨率可以通过换能器的数量的影响。本文对提高无碴轨道分层识别的计算性能和成像精度具有一定的参考价值。
This paper aims to adopt the total focusing method (TFM) and wavenumber method for characterizing a delamination in ballastless slab track. Twelve dry point contact (DPC) transducers located at the upper surface of the slab track compose a linear array. These transducers are employed to actuate shear waves, which are suitable for identifying the delamination. The technique of removing the surface wave has been implemented for only retaining the scattered wave caused by the delamination and the reflected wave from the bottom of bed plate. Numerical and experimental results demonstrate that the delamination and bottom of the bed plate can be identified by the proposed methods. Furthermore, the near-surface pseudomorphism is distinctly restrained after removing the surface wave. Compared to TFM, the wavenumber method has the great advantages of improving computational performance and lateral resolution. However, they have no significant difference in the longitudinal resolution. Furthermore, it has been confirmed that the lateral resolution can be affected by the amount of transducers. This paper can provide valuable suggestions on improving the computational performance and the imaging accuracy when we identify a delamination in ballastless slab track.