METHODS FOR DIAGNOSTICS OF COMPOSITE STRUCTURES BY FIBER OPTICAL SENSORS

The paper substantiates the relevance of the application and presents the results of researches of methods and means of continuous diagnostics of composite structures using point, quasi-distributed and distributed fiber-optic sensors. A mathematical description and results of theoretical researches of the method of two optical fibers for simultaneous measuring of deformation and temperature, a method of testing stresses of composite structures with integrated fiber-optic strain sensors and acoustic emission are presented. An optical testing method has been proposed that makes it possible to reduce the error in determining deformation by half by minimizing microslippage and increasing adhesion at the interface between «the protective coating of the sensor and the polymer matrix of the composite» through special treatment of optical fibers in a solution of polysulfone in dimethylformamide before integration into the material. Experimental researches of the developed methods confirmed the adequacy of the proposed mathematical models in practice. Based on the results of the research, technologies and instrumentation have been developed for optical monitoring of a wide class of composite structures during testing and operation, including in the conditions of the Far North and exposure to high-voltage lightning discharges.