Studium plastometrických zkoušek a možnosti jejich aplikací

Abstract

This Ph.D. thesis deals with the provision of a comprehensive and clear set of information about plastometric tests and the possibilities of their applications. The work will be presented today the most widely used modern technologies of testing deformation characteristics of the materials. We introduce a number of equations used to calculate the strain, strain rate and stress from torsion and compression tests. In addition, I compare these equations with computer simulation using finite element method. The main point of the work is the possibility of application of results plastometric tests. It will be a compilation of mathematical description of stress - strain curves by calculating the activation energy and other constants. Furthermore, the description of the stress strain curves based on the principle of two opposite acting forces. The paper will present options for calculating the degree of softening. The degree of softening will count from intermittent compression or torsion tests, and from in our department untried method of stress relaxation, calculated from the data of continuous testing. Continuous set of tests can be also used to calculate the dissipation of energy and for the computer simulation of forming efficiency. The real test will be performed as the study material for microstructure and microhardness testing. All the points mentioned in this paragraph will be complemented by the results of my work.