Axial force sensor for screw bolt using optical fiber grating for detection of strain

Abstract

In this study, an axial force sensor was developed and evaluated for a screw bolt using optical fiber grating (FBG: fiber Bragg grating). This sensor has high tolerance to electromagnetic noise. Furthermore, it has a characteristic long-distance signal transmission ability because it was made using optical fiber. This washer type sensor forms a circular projection because the stress distribution in the sensor is obtained only proportional to the axial force of the screw bolt. The axial force sensor was experimentally developed for an M10 screw bolt. According to test results, the reflection wavelength shift was proportional to the axial force, implying that this sensor has excellent characteristics.