NODAL SENSITIVITIES AS ERROR-ESTIMATES IN COMPUTATIONAL MECHANICS

This paper proposes the use of special sensitivities, called nodal sen sitivities, as error indicators and estimators for numerical analysis in mechanics. Nodal sensitivities are defined as rates of change of re sponse quantities with respect to nodal positions. Direct analytical d ifferentiation is used to obtain the sensitivities, and the infinitesi mal perturbations of the nodes are forced to lie along the elements. T he idea proposed here can be used in conjunction with general purpose computational methods such as the Finite Element Method (FEM), the Bou ndary Element Method (BEM) or the Finite Difference Method (FDM); howe ver, the BEM is the method of choice in this paper. The performance of the error indicators is evaluated through two numerical examples in l inear elasticity.