Use of hybrid mixed finite element models for the characterisation of the boundary layer in Reissner-Mindlin plates

In this paper the nonconventional finite element formulations being developed at IST are used to study a boundary layer. Hybrid mixed finite elements with approximations based on Legendre polynomials are used to characterise the high stress gradients, which occur near the edges of "thin" bending plates for which the Reissner-Mindlin behaviour is assumed. This study is performed on a square plate for different boundary conditions. For the case of the soft simply supported plate the behaviour of the formulation that was used is studied in detail. A numerical characterisation of the boundary layer for different thicknesses is also performed.