基于光纤光栅的钢轨应变测量关键技术研究

Key Techniques for Rail Strain Measurements Based on Fiber Bragg Grating Sensor

钢轨应变的监测在铁路线路的运营维护中具有重要意义。光纤光栅传感器相比传统传感器在稳定性、抗电磁干扰与准分布式测量等方面能够更好满足钢轨应变测量的需要。本文指出了光纤光栅传感器对载荷和温度应力的测量原理,建立光纤光栅中心反射波长漂移量与载荷和温度应力产生的钢轨应变的数学模型。使用光纤光栅传感器进行温度应力和动态载荷下的钢轨应变监测实验,并通过匹配光栅方法消除温度变化的干扰。实验结果表明光纤光栅应变传感器适用于钢轨应变的监测需要,具有良好的工作性能。

Monitoring of rail strains is important in railway transportation and maintenance. Fiber bragg grating （FBG） sensors are better than traditional sensors in terms of stability, immunity to electromagnetic interfer- ence and feasibility of semi-distributed measurement, therefore they are more suitable to rail strain measure- ments. We discuss the mechanism of wavelength shifting under load strains and temperature stresses. Monito- ring experiments of rail strains under the action of temperature stresses and dynamic loads are performed, and the effect of temperature variations is eliminated using the matched-grating method. Results indicate that FBG sensors can be used to measure and monitor rail strains with good performance.