Inelasticity Variants of the Theory.
Problems of reliable functioning and materials consumption decrease for modern technique constructions operating under conditions of high level of power and temperature loadings, and ionizing radiation as well make a problem of mathematical modelling of nonelastic behavior and constructions destruction rather urgent.
The increase in working parameters of modern machines and devices leads to increase of both of the general and local intensity of the constructions. Real loading processes for such constructions lead to nonelastic (viscous-plastic) deformations.
Thus the loading is a complex nonisothermal one, and a mode of its' changes may be one of the most any under conditions of repeated and continuous influence of the thermal power loadings and ionizing radiation. Theories of plasticity, creep and nonelasticity based on the nonisothermal loading now-in-use lead to the authentic results under narrow limited conditions only, when loadings are close to ordinary and stationary.
Separated examination of processes of plasticity, creep and damage accumulation without considering of their mutual influence is practically proper to all theories applied in calculations. Such prominent aspects influencing damage accumulation as brittle behavior and healing are not considered practically.
All it essentially limits areas of applicability of the theories of plasticity, creep and kinetic equations of damage accumulation (criteria of destruction) used in calculations.
The theory of nonelasticity belongs to the class of single-surface theories of flow under the combined loading. Comparisons of calculations under various theories of plasticity, creep and nonelasticity have shown that the results received by the means of the developed theory of nonelasticity are the best to correspond to the experimental data.
On the basis of these researches the conclusion is drawn that the developed theory of nonelasticity can be applied to practical calculations of nonelastic behavior and material damage accumulation of construction material under unrestricted process of complex nonisothermal loading. And authentic forecast for lifetime of high rating construction material under repeated and continuous influence of the thermal power loadings and ionizing radiation can be made on the basis of this theory.
The range of application of the theory of nonelasticity is limited by small strain of homogeneous and initially isotropic metals at temperatures when there is no phase transformation, and deformation rates when dynamic effects can be neglected.