METHOD FOR DIFFERENTIAL EVALUATION OF DAMAGE STAGES OF ARTICLE MADE FROM COMPOSITE MATERIAL Russian patent published in 2024 - IPC G01N29/14 

FIELD: measurement.

SUBSTANCE: use for differential evaluation of damage stages of an article made from composite material. Essence of the invention consists in the fact that at least one fibre-optic line is integrated into an article made from a composite material, at the manufacturing stage, loading an article from a composite material made with an integrated fibre-optic line, exposure of the fibre-optic line to an acoustic signal, their registration and subsequent determination of the damage of the article based on the obtained data, wherein acoustic emission signals are recorded by an amplitude-threshold method with selecting a sequence of "events", namely, waveforms of different amplitude and duration of acoustic signals, followed by frequency filtering of noise to each said "event" by using a low-pass filter with angular frequency of 200 Hz, then calculating the energy of acoustic signals recorded by the interferometric method in the fibre-optic line, in the form of a sum of squares of amplitudes, and by means of averaging method in a sliding time window with length of 1 second without overlapping, a uniform time series of energies u_i of optical fibre signals is determined, then, using quantitative recurrent analysis of previously obtained time series of acoustic signals from optical fibre, calculating recurrent matrix, then constructing a recurrent diagram of dependence of energies u_i of acoustic signals of optical fibre on time, and differential assessment of stages of damage of article made from composite material, according to the indicator "laminarity" LAM, which shows fraction of points forming vertical lines on recurrent diagram.

EFFECT: provision of possibility of differential assessment of stages of damage of product, which characterizes both intermediate stages of damages, and critical stage of damage, with simultaneous establishment of critical points of transition of one stage of damage to another.

1 cl, 6 dwg