An adaptive displacement/pressure finite element scheme for treating incompressibility effects in elasto-plastic materials

In this note a mixed finite element formulation is described for coping with (nearly) incompressible behaviour in elasto-plastic problems. In addition to the displacements an auxiliary variable, playing the role of a pressure, is introduced resulting in Stokes-like problems. The discretisation is done by a stabilised conforming Q1/Q1-element and the corresponding algebraic systems are solved by an adaptive multigrid scheme using a smoother of block Gauss-Seidel type. The adaptive algorithm is based on the general concept of using duality arguments to obtain weighted a posteriori error bounds. This procedure is carred out here for the described discretisation of elasto-plastic problems. Efficiency and reliability of the proposed adaptive method is demonstrated at (plane strain) model problems. (orig.)Available from TIB Hannover: RR 1606(98-33) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman