The Finite Element Method in Thermosetting Polymers' and FRPs' Supramolecular Structure and Thermomechanical Properties' Modeling.

The object of research is cured thermosetting epoxy polymer and FRP on the base of the same polymer matrix. The purpose of this research is to develop the finite element (FE) method in the modeling of cured thermosetting polymers and FRPs to predict their mechanical and thermal properties. The structural mathematical modeling with subsequent computer FE modeling was performed. The results of FE modeling were compared with the experimental data of cured polymer's and FRP's tensile strength and deformations under mechanical load at different temperatures. The design of the polymer's FE model was based on the tetrahedral supramolecular structure and then transformed into FRP's model by integrating glass fiber rods. Using the structural density as the structure model's parameter, the relative size and disposition of the finite elements were determined. The viscoelastic properties are set in the model by regulating the structural density and compressive/tensile properties of joints. The long-term plastic deformation and stress relaxation were determined as the result of the supramolecular structure's inner shearing with the decrease of its structural density. The FE models of the cured epoxy polymer and FRP were developed, making it possible to predict short-term and long-term deformations under load with high accuracy considering the temperature factor.