DIAGNOSTIC METHOD OF RELIABILITY AND LIMITED LIFE OF MULTI-LAYER STRUCTURES MADE FROM COMPOSITE MATERIALS OPERATION Russian patent published in 2017 - IPC G01N25/72 

FIELD: measuring equipment.

SUBSTANCE: method and device, implementing this method includes placing of optical fibers with Bragg gratings layer by layer in the structure layers from polymer composite materials in the manufacturing process. The gratings coordinates of different optical fibers are set one above the other with the error of not more than half of the grating length. The temperature and deformation are measured, the values of the strains on the gratings due to deformation and temperature are determined by solving the systems of equations, describing the corresponding mathematical models. During the product loading process, the deformation values and the temperature are compared with the maximum permissible deformation and temperature. Measure the dependence of the voltage and temperature values on the gratings from the depth of its occurrence in the structure. Measure the difference between the measured and reference dependencies and, based on the comparison, form the conclusion on the structure reliability under the action of power loads and the maximum service life. Based on the results of the temperature measured along the optical fibers, the areas of the stress concentrators position are localized.

EFFECT: increasing the detection reliability of the local reduced strength areas, increasing the result reliability of evaluating the technical and operational status of complex structures and its elements made of composite materials.

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