Adaptive control for finite element analysis in plasticity

An error on the constitutive law, called dissipation error, is used to meas ure and to enhance the quality of finite element computations of plastic st ructures whose behaviour is described by internal variables. This measure t akes into account all the classical sources of error involved in the comput ation: the space discretization (the mesh), the time discretization and the iterative technique used to solve the nonlinear discrete problem. To quant ify more specifically the contribution of these three error sources to the error, three error indicators are calculated: a space indicator, a time ind icator and an iteration indicator. Then, the error and the three indicators are used in an adaptive strategy: the space indicator allows us to adapt t he mesh. the time indicator to adapt the time discretization and the iterat ion indicator makes it possible to limit the number of iterations of the gl obal iterative algorithm. (C) 1999 Civil-Comp Ltd and Elsevier Science Ltd. All rights reserved.