Constitutive-relation-error-based a posteriori error bounds for a class of elliptic variational inequalities

On the basis of the dual variational formulation of a class of elliptic variational inequalities, a constitutive relation error is defined for the variational inequalities as an a posteriori error estimator, which is shown to guarantee strict upper bounds of the global energy-norm errors of kinematically admissible solutions. A numerical example is presented to validate the strictly bounding property of the constitutive relation error for the variational inequalities in question.