Physical Properties Of Materials That Determine Reversible And Irreversible Deformations

Yu. A.Alyushin

National University of Science and Technology MISIS, Moscow, 119991, (RUSSIA)

PAGE NO: 39-56

ABSTRACT – DOI : https://dx.doi.org/10.47204/EMSR.1.1.2020.039-056

The mechanisms of reversible and irreversible deformations are considered using a model of mechanics based on the concepts of space, time and energy. Local energy, as a generalized scalar function, is represented as a linear combination of independent invariants of the equations of motion in the form of Lagrange with the addition of terms that characterize the processes of dissipation and hardening. The use of material density as a General factor of physical properties involved in the mathematical formulation of the concept of “energy”, which determines the scale of the energy scale for all types of energy manifested in the movement of solids, is justified. Arguments are given in favor of switching to a new scale of average stresses, including on the basis of comparing changes in potential and elastic energy during deformation under the influence of its own weight. A variant of experimental determination characteristics of the elastic properties is proposed. The possibilities of spontaneous processes of energy transfer from one form to another within one invariant for elastic deformation and with simultaneous change of several invariants for irreversible deformation are noted. An interpretation of the coefficients associated with the physical properties of the material in the field of irreversible deformations is proposed using the unified curve hypothesis and the theory of plastic flow. The determining role of density, heat capacity and coefficient of linear expansion of the material in the processes of deformation and the energy state of particles is proved.