Onyshchenko I. Description of viscoplastic flow of metals in a wide range of values of temperature and strain rate

The object of study is viscoplastic in a wide range of temperatures and strain rates. The purpose of research is to build a theory of viscoplastic constitutive relations for a wide range of temperatures and strain rates in arbitrary loading. Research methods and apparatus are analytical formulation of the theory and numerical methods of its implementation on PC. Theoretical and practical results are the development of the theory of viscoplastic, which allows you to calculate the deformation at any load over a wide temperature range and strain rates. New. A new local law formulated viscosity, it is allowed to simplify the defining relations theory microstrain at small strains by reducing the number of parameters of the theory. Implicit numerical integration method is adapted, it is possible to more efficiently carry out calculations to compare theoretical results with experimental data. Ratio viscoplastic theory presented in the form of a continuous built using the operator tangent stiffness for both small and finite deformations. The generalized continuum theory hipoelastic-viscoplastic formulated for finite deformations. Hipoelastic-viscoplastic version of the theory, which takes into account microstrain formulated at final deformations in a wide range of temperatures and strain rates values. Numerical study of a thin-walled tube deformation carried out at final deformations, and the theory of comparative calculation results with the experimental data. The degree of implementation is that the results are introduced in the educational process Oles Honchar Dnipropetrovsk National University in the discipline "The theory of Creep." The scope of use is in the construction and mechanical engineering.