Fiber Bragg gratings strain measuring system and a sensor calibration setup based on mechanical nanomotion transducer

摘要

Fiber Bragg grating (FBG) strain sensors are important instruments for health monitoring and structural control applications. We present a 16-channels FBG strain measuring system with a built-in unit for a spectral calibration. Our goal is to reduce the error of strain measurements. In this regard, we paid close attention to the FBG sensors themselves. FBG sensor features of fabrication technologies can lead to a non-linear behavior of a FBG sensor, that affects the errors of the strain measurements. Here we present a nondestructive calibration method for FBG strain sensors that use a mechanical nanomotion transducer. The principle of operation and main technical characteristics of mechanical nanomotion transducer are described in this paper. A customized calibration setup was designed based on dovetail-type slideways that were mechanized using a stepping motor. The performance of the FBG strain sensor was investigated through analysis of experimental data, and the calibration curves for the FBG strain sensor are presented.