Current lines for Prandtl solution

The authors consider plasticity equations in a stationary two-dimensional case. For Prandtl solution, which describes the compression of plastic layer by rigid plates, the authors consider two velocity fields. The first one is Nadai solution, the second one is the new solution. The authors prove that the current lines in these solutions coincide. Based on the principle of maximum dissipation, the spheres of usage of these velocity fields are defined.