Some Aspects of Invariant Theory in Plasticity. Part 2: Constitutive Relationsfor Perfectly Locking Materials. Comments on Perfectly Plastic Solids

摘要

The aim of this contribution is twofold. Firstly, by using the representationtheory of isotropic tensor functions, general form of the constitutive relationship for perfectly locking materials is derived. The homogeneity condition of degree zero imposed on the locking behavior permits to obtain the general form of the locking locus. Some particular cases are also studied. Secondly, to account for the dissipation density dependent on hydrostatic pressure, the theory proposed by Sawczuk and Stutz is generalized. Consequently, incompressible behavior of isotropic perfectly plastic materials obeying pressure sensitive yield condition is described.