Algorithms for solving the plasticity theory problems by the finite element method

Considered are the methods of solving the problems of plasticity connected with the problems of ensuring the equipment reliability at large power units. The shortcomings of the iteration scheme of the nonlinear problem solution are analyzed and a new procedure having better convergence and stability is proposed. The distinctive feature of the new scheme is the fact that the iteration process is carried out by misfits an by displacement like in the old scheme. It is noted that the proposed scheme permits to obtain solutions for developed plastic zones and under the condition of a plane stressed states. It is emphasized that the new iteration process will permit to solve elastic-plastic problems for construcitons operating under stresses close to the creep limit and due to that having developed plastic zones in the region of sharp concentrators and cracks