Issue 49

V. Matveenko et alii, Frattura ed Integrità Strutturale, 49 (2019) 177-189; DOI: 10.3221/IGF-ESIS.49.19 184 and the corresponding strain in the material in the vicinity of the fiber is controlled in the calculations. Further, the values * 1   and * 2   are taken as experimental data to calculate the strain 3 exp  along the fiber based on the Eq. (4). Then the error between the strain 3  and 3 exp  is estimated. In Tab. 3 the values 1 2 3 * * * , ,    ,   ** 1   ,   ** 2   and the magnitude of the errors 1  and 2  are shown. Here 1 * 1 o u    , 2 * 2 o u    , 3 * 3 o u    ; * * 1 1 2 2 , / / o o u u                                   . The error in the calculation of strain based on the Eq. (4) is determined as follows:   1 1 3 3 3 100% exp        ,   2 exp 2 3 3 3 100%        , where 1 exp 1 3 * 1 k      , 2 exp 2 3 * 1 k      . Tab. 3 also shows the values of 1 k and 2 k , which, according to the formulas * 1 1 3 k      , * 2 2 3 k      , provide reliable strain values. Layered model with the formation of a resin pocket [90/90] 1 *  2 *  3 *    ** 1     ** 2   1 k 1  % 2 k 2  % 0 x u u  -74.01 -94.32 500.00 389.88 393.09 0.78 0.03 0.79 0.79 0 y u u  106.31 -84.90 -22.26 -35.46 -5.18 1.59 104.22 0.23 70.16 0 z u u  113.62 10.08 -35.27 -42.65 -59.05 1.21 55.05 1.67 114.66 Homogeneous model with the formation of a resin pocket 1 *  2 *  3 *    ** 1     ** 2   1 k 1  % 2 k 2  % 0 x u u  -74.15 -94.17 500.00 389.90 393.07 0.78 0.02 0.79 0.79 0 y u u  91.54 -53.13 -20.02 -35.96 -13.04 1.80 130.28 0.65 16.46 0 z u u  108.86 10.29 -30.49 -43.47 -59.08 1.43 82.76 1.94 148.40 Layered model without the formation of a resin pocket [0/0] 1 *  2 *  3 *    ** 1     ** 2   1 k 1  % 2 k 2  % 0 x u u  -64.57 -96.30 500.00 387.43 392.45 0.77 0.66 0.78 0.63 0 y u u  86.79 -27.76 -14.02 -31.33 -13.19 2.23 186.51 0.94 20.64 0 z u u  92.21 7.86 -23.99 -31.22 -44.58 1.30 66.83 1.86 138.22 Homogeneous model without the formation of a resin pocket 1 *  2 *  3 *    ** 1     ** 2   1 k 1  % 2 k 2  % 0 x u u  -74.30 -94.93 500.00 390.04 393.31 0.78 0.01 0.79 0.85 0 y u u  403.99 -147.25 -18.58 -105.69 -18.39 5.69 629.14 0.99 26.85 0 z u u  104.11 -13.96 -28.63 -25.16 -43.86 0.88 12.65 1.53 96.38 Table 3 : The results of the evaluation of the limits of applicability of relations (4) on a model of a cube with integrated optical fiber.