ERROR-ESTIMATES FOR FINITE-ELEMENT SOLUTIONS OF ELLIPTIC BOUNDARY-VALUE-PROBLEMS

A error estimate for the finite element solutions of elliptic boundary value problems is introduced. The error measure is defined by the ene rgy-norm distance between the kinematically admissible stress field co mputed by the displacement finite element method, and a quasi-statical ly admissible stress field. The error estimate is defined using this d istance normalized by the total strain energy of the deformed body. Th e element contribution to the above error estimate is used to define a n error indicator and a local error measure which can be used in adapt ive finite element method as a criteria for mesh refinement. This meth od of error estimate can be implemented in existing finite element pro grams in a straightforward manner.