The complex modeling of short- and long-term deformation of a cured thermosetting polymer under thermomechanical load using the finite element method

The object of research is a cured thermoset polymer on the example of cured epoxy polymer. The purpose of this work is to improve the methods of finite element (FE) modeling of the structure of cured thermoset polymers to predict their mechanical, deformative and thermal properties. Method. The structural mathematical modeling method with subsequent computer FE modeling was used. The structure of the FE model was based on the cured polymer's tetrahedral supramolecular structure. Using the structural density as structure model's parameter, the relative size and disposition of the finite elements were determined. The shift from elastic to viscoelastic behavior was controlled by modifying the structural density and compressive/tensile properties of joints. The long-term plastic deformation and stress relaxation were determined as the result of supramolecular structure's inner shearing with the decrease of its structural density. The FE modeling of stress and deformation was realized by LIRA SAPR computer design program. Results. The FE models of the cured epoxy polymer were developed, making it possible to predict short-term and long-term deformations under load with high accuracy considering the temperature factor.

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