• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2025, Vol. 61 ›› Issue (8): 1-8.doi: 10.3901/JME.2025.08.001

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High-sensitive Magnetic Field Sensor Based on Terfenol-D and Fiber Bragg Grating

HE Chaojiang1, LI Peng2, HE Cunfu2, WANG Yujue2, LIU Xiucheng2   

  1. 1. College of Mechanical & Energy Engineering, Beijing University of Technology, Beijing 100124;
    2. College of Information Science and Technology, Beijing University of Technology, Beijing 100124
  • Received:2024-07-13 Revised:2025-01-08 Published:2025-05-10

Abstract: Traditional magnetic field sensors are susceptible to environmental electromagnetic interference, which is difficult to be applied to magnetic nondestructive testing under complex working conditions. Hence, a magnetic field sensor based on Terfenol-D and fiber grating is developed, and a sensor sensitivity enhancement method based on static bias magnetic field tuning is proposed. Firstly, based on the magnetostriction and fiber grating sensing theory, a Terfenol-D based fiber grating magnetic field sensor model is established, and the relationship between the wavelength shift of the fiber grating and the applied magnetic field strength of the Terfenol-D material is analyzed. Secondly, a static bias magnetic field is introduced to pre-magnetize the Terfenol-D material to adjust the detection sensitivity of the sensor to magnetic field changes. The theoretical analysis and experimental test results show that the magnetic field detection sensitivity of the sensor can be effectively improved to 9.38 pm/mT by the tuning of the static bias magnetic field, which is about 8.55 times compared with that of the unoptimized one. Finally, the optimized fiber grating magnetic field sensor based on Terfenol-D is applied to the magnetic leakage detection of steel plate, which not only realizes the defect localization and the quantitative characterization of the defect depth, but also shows better antimagnetic interference ability than that of the traditional Hall sensor.

Key words: magnetostrictive, Terfenol-D, fiber bragg grating, magnetic field sensors, defect detection

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