Ultrasonic surface wave propagation and interaction with surface defects on rail track head
Ultrasonic surface wave propagation and interaction with surface defects on rail track head
复制标题
DOI：
10.1063/1.2184714
复制
发表时间：
2006-03
期刊：
影响因子：
--
通讯作者：
Donald O. Thompson;D. Chimenti
中科院分区：
文献类型：
--
作者：
Donald O. Thompson;D. Chimenti
电磁声换能器（EMAT）是一种能够在金属样品上产生宽带超声表面波的非接触式超声换能器。我们描述了一些基于实验室的超声波测量，使用EMAT产生一个宽带，低频（约50-500 kHz）的超声波表面波，与瑞利波一样的属性上的轨头。迈克尔逊干涉仪已被用来精确地测量绝对的面外位移的超声波产生的轨头上的传播沿着轨头与一个模拟的表面断裂缺陷相互作用。一些能量从缺陷反射，一些能量在缺陷下传播。我们描述了不同的方法，可以用来确定裂纹的存在和深度，并提出了一系列的超声波B扫描的数据。EMAT的非接触性质和我们建议用于测试的一发一收测试几何形状使它们特别适合于高速在线检测和测量裂纹深度。
Electromagnetic acoustic transducers (EMATs) are non-contact ultrasonic transducers capable of generating wide band ultrasonic surface waves on metallic samples. We describe some lab based ultrasonic measurements using EMATs to generate a wide band, low frequency (approximately 50-500 kHz) ultrasonic surface wave, with Rayleigh wave-like properties on a rail head. A Michelson interferometer has been used to accurately measure the absolute out-of-plane displacement of the ultrasonic waves generated on the rail head which propagate along the rail head to interact with a simulated surface breaking defect. Some of the energy is reflected from the defect and some propagates under the defect. We describe different approaches that can be used to determine the presence and depth of the crack and present the data as a range of ultrasonic B-scans. The non-contact nature of EMATs and the pitch-catch test geometry that we propose to use for testing make them especially suitable for online detection and gauging of crack depth at high speed.