METHOD FOR NON-DESTRUCTIVE TESTING OF STRUCTURES FROM COMPOSITE MATERIAL Russian patent published in 2020 - IPC G01B11/16 G01L1/16 

FIELD: measurement technology.

SUBSTANCE: invention relates to non-destructive testing of construction materials – concrete compositions and concrete structures using a fiber-optic sensor with a Bragg grating. Structural control is carried out through real-time monitoring, before arrangement of sensors in volume of composite material, preliminary numerical simulation of analyzed structure is carried out for optimization of zones of arrangement of fiber-optic sensors line on Bragg gratings in composite material – concrete mixture, placing sensors on Bragg gratings discretely, preferably in the zone of expected maximum stress concentrations, where there is a high probability of defect or damage occurrence, and in the zone of moderate stress concentrations in the structure volume, non-destructive testing is carried out in the material volume continuously, starting from the structure formation, using fiber-optic sensors on Bragg gratings, at that during formation process level of technological deformations is monitored in real time; according to the data obtained from fiber-optic sensors on Bragg gratings, phase transitions and levels of technological deformations are tracked. After the structure is formed, the structure is monitored during operation: checking fiber-optic sensors on Bragg gratings for operability by discrete loading of the sample and removing spectrum of the Bragg grating; controlling whether the reflected spectrum has one resonance peak; at a given external single-type load on the controlled structure using fiber-optic sensors on the Bragg gratings, the deformation thereof is fixed by the interrogator when defect or defects appear at any stage of continuous monitoring, starting from the structure formation and during its operation, due to the deformation state change in the defects occurrence area and the relative values change: ε^j_p/ε^j_q, p=1,2, …, k, q=p+1, p+2, …, k (where ε^j_p, ε^j_q – measured components of deformation tensor by means of fiber-optic sensors on Bragg gratings at points p and q for j – version of loads, k is number of controlled points, ε^j_p/ε^j_q=a^j_pq is deformation ratio). Further, the structure is monitored by continuously detecting by the interrogator changes in the deformation state of the structure, preferably in the areas of location of the fiber-optic sensors on the Bragg gratings in the zones of maximum and moderate stress concentrations, at that, on maintaining the integrity of the initial state of the monitored structure, the set of deformation ratio a^j_pq is constant for each of subsequent versions of loads at different values of the number of controlled points (k), and when changing deformation ratio a^j_pq – in a timely manner signaling the appearance of a defect and the development of defectiveness in the vicinity of the monitored points, its location and development.

EFFECT: broader functional capabilities and possibility of improving quality of continuously obtained information in real time on deformation processes occurring in the analyzed composite material.

1 cl, 7 dwg