Superconvergent Patch Recovery for plate problems using statically admissible stress resultant fields

In this paper, we study an approach for recovery of an improved stress resultant eld for plate bending problems, which then is used for a posteriori error estimation of the nite element solution. The new recovery procedure can be classi ed as Superconvergent Patch Recovery (SPR) enhanced with approximate satisfaction of interior equilibrium and natural boundary conditions. The interior equilibrium is satis ed a priori over each nodal patch by selecting polynomial basis functions that ful l the point-wise equilibrium equations. The natural boundary conditions are accounted for in a discrete least-squares manner. The performance of the developed recovery procedure is illustrated by analysing two plate bending problems with known analytical solutions. Compared to the original SPR-method, which usually underestimates the true error, the present approach gives a more conservative error estimate. Copyright