ADAPTIVE FE ANALYSIS OF PLATES BY SHEAR-FLEXIBLE QUADRILATERAL REISSNER-MINDLIN ELEMENTS

h-version adaptive finite element analysis of plates using QUAD4 R-M e lements is discussed. The necessity of using shear flexible formulatio ns for plate elements in adaptive FEA is explained. Two shear flexible QUAD4 plate elements formulated by reconstituted shear strain fields are selected from literature and are used to solve both thin and thick plates with various geometries and boundary conditions. The effect of boundary layers in plates with soft or free boundaries is discussed a nd is shown in various examples. A powerful and versatile quadrilatera l automatic mesh generator (MSD) is used for the discretization of the plate domain. The error norms are computed by the Z(2) as well as the superconvergence theory. The global convergence rates of the adaptive solutions with respect to the energy norms are demonstrated and it is seen that the theoretical rates of convergence are exceeded in severa l cases.