Uniform principle on stress, strain and yield locus for analysing metal forming processes: the contribution of Prof. Z.R. Wang

A new theory concerning a consistent relationship between stress and strain components and associated studies are reviewed. This theory was contributed by Prof. Z.R. Wang. Discussion focuses on the applications of qualitative analyses with respect to metal forming processes. From an application point of view, this theory extends the fundamental concept of plastic stress and strain-rate relations, and then leads to a proposal for the relation between stress and total strain components. Emphasis is given to the theory by which engineering problems can be solved and the simplicity of practical use, such as the relations between stress, strain and yield locus with respect to a metal forming process. Determinations of the locations of typical metal forming processes in plane-stress, or in a three-dimensional stress state are presented.