Analysis of the components of discretization error in non-linear structural problems

The present paper considers the reliability of finite-element analysis where non-linear planar structural problems (large strains and plasticity) are concerned. Error estimators of the flux-projection type, based on strain power density, are used. A study of the various components of error discretization is made as a function of parameters such as load step or the number of degrees of freedom of the finite-element model. Two numerical examples are selected so that certain properties of these estimators are demonstrated. Conclusions of practical use can be drawn from the results expressed in tables and charts.