METHOD OF MEASURING DEFORMATION OF STRUCTURES MADE FROM COMPOSITE MATERIALS Russian patent published in 2011 - IPC G01B11/16 G01L1/24 

FIELD: physics.

SUBSTANCE: optical fibre structure with Bragg lattices is put into composite material during production thereof. The spectral position of peaks of the Bragg lattices is measured after making the structure from the composite material and distribution of mechanical and thermal deformations inside the structure of the composite material is determined by solving the system of equations: , where f(T,ε) is the distribution function of mechanical and thermal deformations on the structure made from composite material (T is the temperature value, ε is the deformation value); f(E_{x, y, z}) is the distribution function of elastic properties of the structure made form composite material, E_{x, y, z} is the Young 's modulus tensor; f(α_{x, y, z}, v_{x, y, z}) is the distribution function of thermal characteristics of the composite material (α_{x, y, z} is the coefficient of volume expansion tensor, v_{x, y, z} is the thermal conductivity coefficient tensor);f(F_load, F_T) is the distribution of mechanical and temperature effects on the structure made from composite material (F_load is the value of the mechanical effect, F_T is the value of the temperature effect); f_FBG(T,ε) is the function of total deformation on the path of the optical fibre with Bragg lattices (T is the temperature value, ε is the deformation value); f_i-FBG(Δλ) is shift transformation function of the position of the i-th peak of the Bragg lattice to the temperature value and deformation (Δλ is the displacement of the peak of the Bragg lattice). The optical fibre contains two or more Bragg lattices which are not more than 5 mm long. The distance between the Bragg lattices and one optical fibre is not less than 5 mm.

EFFECT: high measurement accuracy.

3 cl, 15 dwg