Abstract
In the context of the linear elasticity problem, the quality of Finite Element Analyses (FEA) has been traditionally evaluated using estimations of the error in energy norm of the Finite Element (FE) solution. One of the techniques used to evaluate the error in energy norm is based on the use of an enhanced or recovered solution obtained form the FE solution. This recovered solution is of a higher quality than the FE solution and
therefore it would be interesting to use it as the output of the FE program. However this
would require error estimation and error bounding techniques to evaluate its accuracy.
So far, we can only find a few works in this field which involve a high computational cost. In this work we propose the use of a displacement recovery technique, so-called SPR-CD, that by means of a set of constraints imposed at patch level provides both, an improved kinematically admissible recovered displacement field and also an almost-statically admissible stress recovered field. The recovered stress field is continuous but suffers from a lack of internal and boundary equilibrium. In order to evaluate the quality of the recovered solution, in this work we introduce an a-priori upper bound of the error in energy norm of the recovered stress field, a numerical strategy to evaluate the required constant and the use of an heuristic error estimator for the recovered stress field.
