ИСТИНА

Ensuring the safe operation of structures across the transportation, energy, construction, and other industries is a priority worldwide. The integration of new materials and technologies into real-world engineering systems demands the advancement of existing diagnostic techniques and the development of novel approaches. Polymer composite materials (PCMs), which have seen extensive application in critical and high-load components—particularly in the aerospace industry—require reliable methods for in-situ diagnostics. One of the most promising techniques is the use of embedded fiber-optic systems to monitor the stress-strain state and temperature of such materials under operational conditions. These systems rely on fiber-optic sensors (FOS) that exploit various physical principles. In this work, we employed fiber Bragg gratings (FBGs) as the sensing elements due to their reliability, technological maturity, and commercial availability. We developed a set of requirements for the spatial topology of FOS integration into composite structures produced using both autoclave and out-of-autoclave molding methods. A comprehensive study was conducted on the FOS–PCM interface to assess compatibility and to analyze the local microstructure in regions surrounding the embedded sensors. This helped evaluate potential defects caused by FOS incorporation [1]. Our findings indicate that, under the specified integration conditions, the mechanical properties of the PCM are only minimally affected, while the FOS retain full functionality after exposure to molding processes. Furthermore, the sensors are capable of monitoring both static and dynamic loads up to material failure [2]. We have also developed methods for stress-strain state monitoring of PCM structures. Adapting these techniques to the actual operating conditions of specific components opens the path toward transitioning from scheduled maintenance to condition-based operation.