Effective elastic characteristics of polymeric composites based on binders with high content of epoxy groups, reinforced by chaotically oriented glass fibers and dispersed polytetrafluoroethylene additives

The aim of the work was to build a model and predict the effective elastic characteristics of polymer antifriction composites (tensor elastic moduli, Young’s modulus and Poisson’s ratio). Tribocomposites formed on the basis of epoxy binders with a high content of epoxy groups (EPAF, UP-610, EHD), filled with randomly located short fibers of E-glass and finely dispersed particles of polytetrafluoroethylene were studied. The basis of the proposed predicting method was the generalized singular approximation of random field’s theory used for solving the system of stochastic differential equations of equilibrium of an elastic medium. The effective elastic characteristics of the model tribomaterials were calculated using the self-consistency method. The analysis of the values of the tensor components of effective elastic moduli depending on the composition, microstructure and volume content of fillers made it possible to establish that the studied tribocomposites are characterized by effective elastic properties close to isotropic. This made it possible to carry out a numerical evaluation of the values of Young’s modulus and Poisson’s ratio, reflecting the influence of changes in the volume contents of the components of the studied polymer antifriction composites. Numerical calculations in model tribocomposites allowed to establish that an increase in the volume fraction of polytetrafluoroethylene particles at a fixed concentration ofE-glass fibers leads to a slight decrease in the values of Young’s modulus, and this relationship is approximately linear. In addition, an increase in the concentration of E-glass fibers at a fixed volume content of polytetrafluoroethylene particles leads to a significant increase in the values ofYoung’s modulus according to a nonlinear law. Numerical calculations in the studied tribomaterials also showed that an increase in the volume fraction of any filler fraction is accompanied by a decrease in the values ofPoisson’s ratio, and this relationship is approximately linear.