IMPLICIT STRESS INTEGRATION AND GOVERNING PARAMETER METHOD (GPM) AS A GENERAL CONCEPT FOR INELASTIC MATERIAL MODELS IN THE CODE PAK
Miloš Kojić (DOI: 10.24874/jsscm.2025.19.01.01)
Abstract
In this paper, we give a short overview of the basic concept of stress integration for inelastic material models. This methodology was introduced by the author, initially for thermo-elastic-plastic and creep deformation of metals, termed as ‘effective-stress-function’ (ESF), and then generalized to the ‘governing parameter method’. These formulations were further implemented in several geological material models. The author built this methodology into the finite element program ADINA, while they were introduced into the PAK program by other PAK authors, after publications in the relevant journals given here in the list of references. This methodology has also been extended to other material models cited here in the references, and served as the basic concept for these models. Only a few simple examples are borrowed from our previous publications since numerous applications of the PAK code over decades to real engineering problems are available in references, in various journals, reports, and books; some of these are given in this monograph.
