In the article a description of the behaviour of metallic layers created in the process of physical vacuum deposition on a composite textile substrates during their cyclical bending process is presented. Either the results of experimental research or the theoretical considerations of changes in the structure resistance as a function of the number of fatigue cycles are presented. It was confirmed mathematically that at the beginning of the bending process, in the case of a small number of bends, single cracks appear on the surface of the layer. After exceeding a certain number of bends, the nature of defects on the surface of the layer changes and the dominating mechanism of changes is the widening and elongation of already existing cracks. It has been confirmed mathematically that changes in resistance in these cases depend respectively on the number of bending cycles and next on quadratic value of number of cycles. A correspondence between the mathematical description and experimental results was obtained.