2-DIMENSIONAL ELASTOPLASTICITY - APPROXIMATION BY MIXED FINITE-ELEMENTS

Two-dimensional elastoplastic problems are used to assess the performa nce of a family of mixed finite elements in the non-linear regime. In particular, four-node bilinear quadrilateral elements that exhibit hig h accuracy in coarse meshes are used to simulate plane stress, plane s train, axisymmetric and (shear-deformable) plate bending problems. The excellent performance of these elements is demonstrated with a number of discriminating examples selected from the literature. In addition, agreement is observed in the limit load predicted by the axisymmetric solid and plate bending elements.