Energy estimates of relaxation and creep deformation processes of polymeric materials

Abstract

The article considers energy estimates of nonlinear hereditary relaxation and creep processes. Polymeric materials have pronounced rheological properties including the flexible-chain structure of macromolecules that are in an oriented state and have an amorphous-crystalline structure at the supramolecular level (Pereborova et al., 2020a). According to the current views of structural physicists, at this level, the rheological properties of polymers, as a combination of elasticity, viscoelasticity and plasticity, are formed (Pereborova et al., 2020b). The decomposition of the total deformation value into the corresponding three parts is considered to be a difficult task due to their simultaneous occurrence and further development. Information about the complex pattern of distribution of material particles over relaxation and delay times can be obtained only through a physically-based analytical description of polymeric materials rheology in combination with the measurement of various deformation processes (Pereborova et al., 2020c). The accumulated experience of working with polymeric materials shows that the viscoelastic and plastic components of their deformation depend in a certain way on the level of applied mechanical action (Pereborova et al., 2020d). Hence, it follows that one creep or relaxation curve cannot be used to get any information on the delay or relaxation times (Pereborova et al., 2018a).