Simulation of the process of shrinkage of the conical workpiece of the steam turbine rotor by the semi analytical finite element method

Abstract

The study of stress-strain state (SSS) is an important task from both a theoretical and a practical point of view, encompassing their widespread use in various fields of technology. The purpose of scientific research is to simulate and study the process of shaping of the conical workpiece of the rotor of a steam turbine under dynamic load, taking into account the conditions of contact interaction with the instrument, physical and geometric nonlinearity using the semi-analytical finite elements method (SAFEM). To describe the dynamic deformation of the body of the survey, the initial relations of the spatial problems of the theory of elasticity in the curvilinear coordinate systems are used. By the limit of elasticity, the relationship between stresses and deformations taken in accordance with the equation of the theory of plastic flow under the condition of the current time for the isotopically varying material. The description of the stress-strain state based on the use of initial, transient and final configurations and considered within the framework of the current scheme of physical components. To simulate interacting contact systems, use a special contact element that provides mutual opacity of the individual elements of the design. The most effective approach to solving the problem is to use an administrative variant of methodological approaches that occupy a place among mathematical and social methods. The approximation based on the decomposition of unknown and given functions of a finite-element model along a system of continuous smooth functions and finite-element sampling in the region of the cross section of a finite element. The distribution shifted within the transverse section of the CE described by the bilinear law. The paper considers evolutionary processes that arise during the manufacture of a steam turbine rotor. Namely shrinkage of the conical workpiece at high temperature under the action of dynamic load. A study conducted with variation of the slope angle and friction coefficient on the surface of the contact with the tool having an effect on the tensile and deformation state, as well as the result of changing the form of the meridional section of the finished part during its shrinkage. The offered approach is relevant in the presented software packages oriented on the modern PC.