Constitutive relation error estimators for (visco)plastic finite element analysis with softening

A posteriori error estimators based on constitutive relation residuals have been developed for 20 years, in particular at Cachan. This approach has a strong physical meaning and is quite general. Here, we introduce an extende d constitutive relation error estimators family able to measure the quality of finite element computations of structures which exhibit plastic/viscopl astic behavior with softening. These measures take into account, over the s tudied time interval, all the classical error sources involved in the compu tation : the space discretization (the mesh), the time discretization and t he iterative technique used to solve the nonlinear discrete problem. (C) 19 99 Elsevier Science B.V. All rights reserved.