For the first time the conservation laws for von Mises plasticity equations in three dimensions as well as for plane stress equations are given. In the plane case conservation laws are used to construct characteristics for the Cauchy problem. For the system of the plane strain, the conservation laws are used to solve the free boundary problem for any convex smooth contour loaded with constant normal and zero tangential stresses.
"Conservation Laws of Three-Dimensional Perfect Plasticity Equations under von Mises Yield Criterion." Abstr. Appl. Anal. 2013 (SI06) 1 - 8, 2013. https://doi.org/10.1155/2013/702132