An evaluation of ultrasonic arrays for the static and dynamic measurement of wheel-rail contact pressure and area
An evaluation of ultrasonic arrays for the static and dynamic measurement of wheel-rail contact pressure and area
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DOI：
10.1177/1350650120919889
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发表时间：
2020-04-16
影响因子：
2
通讯作者：
Lewis, Roger
中科院分区：
文献类型：
--
作者：
Brunskill, Henry;Hunter, Andy;Lewis, Roger
铁路车辆车轮与铁轨之间的界面接触条件对任何铁路网络的寿命、安全性和平稳运行至关重要。多年来，工业界和学术界一直在估计、计算和模拟轮轨界面接触压力和面积条件，但尚未实现精确测量动态接触条件的方法。已经采用了使用压敏膜和受控空气流的方法，但这两种方法都是有限的。超声波反射测量法是指将超声波换能器安装在部件的外表面并产生声波的主动超声波。该超声波包通过主介质传播，并从感兴趣的接触界面反射。然后检测反射波形，并使用准静态弹簧模型从信号中提取接触面积和界面刚度信息。刚度可以通过执行简单的校准程序与接触压力相关。以前的接触压力测量工作依赖于使用聚焦传感器和二维扫描布置，这导致轮轨接触的高分辨率图像，但仅限于从车轮和轨道切割的试样的静态加载。本文所描述的工作已经评估了使用安装在轨道上的64个超声波元件的阵列测量动态轮轨接触补丁的可行性。每个元件按顺序单独脉冲，以建立界面的线性横截面压力分布测量。然后对这些横截面的线测量值进行处理和整理，得到二维接触压力分布。在不同的速度和负载下进行了测量。
The interfacial contact conditions between a railway vehicle wheel and the rail are paramount to the lifespan, safety and smooth operation of any rail network. The wheel-rail interface contact pressure and area conditions have been estimated, calculated and simulated by industry and academia for many years, but a method of accurately measuring dynamic contact conditions has yet to be realised. Methods using pressure-sensitive films and controlled air flow have been employed, but both are limited. Ultrasonic reflectometry is the term given to active ultrasonics in which an ultrasonic transducer is mounted on the outer surface of a component and a sound wave is generated. This ultrasonic wave packet propagates through the host medium and reflects off the contacting interface of interest. The reflected waveform is then detected and contact area and interfacial stiffness information can be extracted from the signal using the quasi-static spring model. Stiffness can be related to contact pressure by performing a simple calibration procedure. Previous contact pressure measurement work has relied on using a focusing transducer and a two-dimensional scanning arrangement which results in a high-resolution image of the wheel-rail contact, but is limited to static loading of a specimen cut from a wheel and rail. The work described in this paper has assessed the feasibility of measuring a dynamic wheel-rail contact patch using an array of 64 ultrasonic elements mounted in the rail. Each element is individually pulsed in sequence to build up a linear cross-sectional pressure profile measurement of the interface. These cross-sectional, line measurements are then processed and collated resulting in a two-dimensional contact pressure profile. Measurements have been taken at different speeds and loads.