Features of Distributions of Local Elastic Strains in Single-Layer Composite Materials

An analysis of the influence of the direction of reinforcement in a composite material relative to the cyclic load on the heterogeneity of the distribution of local elastic strains measured by the thermal method of nondestructive testing is presented. In this study, the possibility of assessing the local distribution of stresses (strains) in the test object is demonstrated using the thermoelastic effect. The temperature field of the thermogram depends linearly on the stresses and strains at local points of the test object. Thermograms of laminates made of composite material with different arrangements of fibrous filler (fiberglass) with an epoxy matrix under cyclic loading were studied. To analyze the differences in the local distribution of strains, statistical data were used and variation coefficients were calculated. To visualize the strain levels, the clustering method and averaging of the temperature distribution values over the length of the laminates were used. The numerical characteristics of local temperature distributions were obtained, which showed a more uniform distribution when reinforcing the material in the direction of loading of the part.