Hybrid fiber Bragg grating sensor for vibration and temperature monitoring of a train bearing

Abstract

We report a fiber Bragg grating (FBG)-based sensor for the simultaneous measurement of a train bearing’s vibration and temperature. A pre-stretched optical fiber with an FBG and a mass is designed for axial vibration sensing. Another multiplexed FBG is embedded in a selected copper-based alloy with a high thermal expansion to detect temperature. Experiments show that the sensor possesses a high resonant frequency of 970 Hz, an acceleration sensitivity of 27.28 pm/g, and a high temperature sensitivity of 35.165 pm/°C. A resonant excitation test is also carried out that demonstrates the robustness and reliability of the sensor.