In continuation of our work on yield surfaces

Part- 1 (http://imechanica.org/node/9016)

Part- 2 (http://imechanica.org/node/9073) and

Part- 3 (http://imechanica.org/node/9103) 

It is essential to know the amount of springback for a given forming process, so that the process or the design of the tool can be modified to obtain the desired product shape. This requires a comprehensive understanding of loading and unloading processes, and determination of elastic constants with finite plastic deformation which, in turn, require precise determination of subsequent yield surfaces.

Please see attachment for ES241 final presentation--general theory of finite deformation

Classical plasticity models evolve state variables in a spatially independent manner through (local) ordinary differen- 

tial equations, such as in the update of the rotation field in crystal plasticity. A continuity condition is derived for the