CRACK OPENING RATE MEASURING DEVICE Russian patent published in 2023 - IPC G01B11/02 

FIELD: measuring methods.

SUBSTANCE: studying processes of destruction of materials for measuring the magnitude and rate of crack opening. The device contains one or more optical fibers with Bragg gratings with a reflection coefficient at a resonant wavelength from 10 to 90%, optical fibers are fixed on the surface of the material, the attachment points of the optical fibers are located at a distance of 10 mm to 20 mm, the output end of the optical fiber with Bragg gratings is connected to its photodetector, one or more semiconductor lasers are connected to one or more optical fibers with Bragg gratings through fiber circulators, the port of each of the circulators is connected to its photodetector, spectrum half-width_LD radiation of a semiconductor laser is chosen significantly less than the half-width of the spectrum_FBG reflections of the fiber Bragg grating, photodetectors and the pulse synchronizer of the current generator are connected to the outputs of a multichannel analog-to-digital converter, the crack opening rate is determined from the delay time between the pulse synchronizer signal and the signal of the reflected radiation by the Bragg grating.

EFFECT: decrease in the sensitivity of the device to pulsed electromagnetic interference and an increase in thermal stability.

1 cl, 2 dwg