钢轨应力检测中超声导波模态选取方法研究  

Research on method for mode selection of guided ultrasonic waves in stress measurement of rails

作　　者：许西宁[1,2] 叶阳升[1] 江成[1] 余祖俊[2] 柯在田[1] 

机构地区：[1]中国铁道科学研究院铁道建筑研究所,北京100081 [2]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《仪器仪表学报》2014年第11期2473-2483,共11页Chinese Journal of Scientific Instrument

基　　金：中国铁道科学研究院院基金课题(2014YJ022)资助

摘　　要：钢轨横截面形状复杂,其内部可传播的导波模态数量众多,为了选取适于检测钢轨内部温度应力的模态,本文提出了一种导波模态选取的指标模型。该模型基于频率、应力敏感度、振型、激励位置偏离度、模态可辨识度五个因子构建,通过分别求解五个因子的数值,综合得到模型的计算结果,最终选取了计算结果数值最大、其值为0.88的导波模态。经实验室和西宝高速铁路现场测试,本文提出的指标模型,能快速、准确选取适于应力检测的导波模态,所选取的模态对应力敏感,在应力变化137 MPa时,其群速度变化值达到2.2 m/s,该模态激励方式简单,易于控制,传播距离超过1km,适用于无缝线路钢轨长距离平均温度应力的在线监测。The rail cross-section has a complex geometry with one vertical axis of symmetry, so the dispersion curves of guided ultrasonic waves in the rail are very complex. In order to select an optimal guided wave mode for stress measurement of rails, an indicator model is proposed based on frequency, stress sensitivity, mode of vibration, exciting position and the mode identification those five factors. By solving the value of the five factors, the integrated results of the model can be obtained. The guided wave mode of the maximum calculated value（0.88） is finally selected. By laboratory and field testing in Xi＇an-Baoji high-speed railway, the guided wave mode suitable for stress testing can be selected quickly and accurately by this indicator model. This mode is sensitive to stress, its group velocity value changes 2.2m/s when stress changes 137 MPa. It has long propagation distance up to 1km. This mode is easy to excite and used, it is very suitable for stress monitoring in continuous welded rails.

关 键 词：超声导波 指标模型 频散曲线 应力敏感度 激励响应 

分 类 号：TB553[理学—物理] TH878[理学—声学]