An implicit return mapping algorithm for anisotropic plasticity with mixed non-linear kinematic-isotropic hardening

Advanced material models can be used to simulate most of the characteristics of sheet metal subjected to plastic deformation. Commercial Finite Element (FE) codes are limited in terms of available advanced material models. Therefore the authors developed and implemented into FE an advanced anisotropic material model using UMAT in which the implicit radial return mapping was used. The model can be used for any yield criterion combined with mixed non-linear kinematic hardening and isotropic hardening (NLK-IH) originating from the Armstrong-Frederick hardening model and later developed by Chaboche. This paper discusses in detail the integration algorithm used for the implemented UMAT. This material model will improve the modelling capabilities for sheet metal forming processes, such as the prediction of earing in cup drawing and springback in U bend operations.

Jaar van publicatie:2011