Three-dimensional analysis of the stress-strain state in the process of plastic deformation of metals

The mathematical simulation of forging, rolling, cutting, etc., aimed at im proving these deformation processes, is accompanied by the calculation of t he strain and stress fields in the product being worked. This paper present s a review of articles published in J. Mater. Process. Tech. in 1996 enabli ng one to state that, as a rule, it is the upper-bound estimate technique a nd the finite-element method that are applied to the calculation of the str ess-strain state. These methods offer good results in defining flow kinemat ics and deformation force. However, despite the practical importance of kno wing the stress state there are few papers dealing with the calculation of stress fields, and the available solution results do not seem to be satisfa ctory. This paper shows why they should be considered unsatisfactory and wh at should be done (what methods should be applied) to improve the predicted stress field without losing the accuracy of prediction of flow kinematics. Discussion on a new method for three-dimensional analysis of stresses and strains is illustrated by a simple example of parallelepiped forging. This paper is, partially, a review of some works published in Russian, which, un fortunately, seem to be unknown to the English-speaking reader. (C) 1999 El sevier Science S.A. All rights reserved.