The work is devoted to the consideration of methods for determining the strain of objects using fiber Bragg gratings under a high-frequency vibration or pulsed mechanical action, which is difficult to perform using widespread methods and devices. The methods are based on numerical processing of the time dependence of the radiation power reflected from the fiber Bragg grating at various wavelengths, which makes it possible to measure strain parameters in a wide range of magnitude and frequencies. The efficiency of the proposed methods is demonstrated by numerical simulation. It is shown that it is possible to restore the strain dependence on time in the range $\pm 1000$ $\mathsf{\mu }\mathsf{ϵ}$ or more from simultaneously measured power dependencies reflected by the fiber Bragg grating using common fiber-optic components. The case of sequential registration of reflected radiation power at different wavelengths to determine the probability density of the distribution of the strain values is also considered. The results of signal processing obtained both by numerical simulation and experimentally for the case of a linear vibration are presented. The technical problems of using the proposed methods are discussed.

Practical guidelines are presented for the optimal placement of fiber Bragg grating (FBG) sensors in reinforced concrete elements aimed at improving the accuracy and reliability of structural health monitoring systems. The study addresses the problem of inefficient sensor distribution, which can lead to increased costs and reduced sensitivity to local damage. Stressstrain zones were identified using finite element modeling in ANSYS and validated through laboratory experiments on reinforced concrete specimens subjected to static and cyclic loading. Three sensor layouts – linear, diagonal, and combined – were systematically analyzed and compared. The combined layout demonstrated the lowest average measurement error of 3.1% while requiring fewer sensors than the other configurations. Numerical simulations confirmed that this layout corresponds to regions of maximum deformation and tensile stress. The results show that optimized sensor placement enhances monitoring accuracy, reduces system cost, and enables early detection of crack initiation in concrete structures.