Research and application of fiber-optic sensors for monitoring the condition of metal structures

Abstract

This article focuses on fiber-optic sensor systems designed for real-time structural health monitoring of metal constructions. The research demonstrates that traditional visual and ultrasonic inspection methods are ineffective in real-time applications, highlighting the need to replace them with sensors capable of operating with an accuracy of ±1 microstrain (µε). The technical characteristics of FBG, DOFS, and BOTDA sensors were comparatively analyzed. For example, the DOFS system is capable of continuous monitoring over distances up to 40 km, while BOTDA provides spatial resolution of 1 meter but registers a signal-to-noise ratio of 10 – 12 dB. The influence of environmental factors such as temperature and humidity was also investigated, revealing a 12% decrease in sensor sensitivity under 90% humidity conditions. The proposed model is adapted to Kazakhstan’s climatic conditions ranging from – 40°C to + 60°C, enabling monitoring of structures up to 10 – 15 km long with ± 1 µε precision. The system utilizes SMF - 28 fiber, FBG sensors, and algorithms written in Python. Installation costs were reduced by up to 25 – 30%, and energy consumption remained between 5 and 10 W. The Python-based data processing system reduced false positives by up to 25% and enabled early fault detection. This system allows efficient and cost - effective real-time monitoring of bridges, pipelines, and industrial structures.