Numerical analysis of strain localization in metal powder-forming processes

It is well known that strain localization and indeed displacement discontinuity can arise in materials exhibiting plastic behaviour. Indeed such localization is almost certain to occur if strain softening or non-associated behaviour exists, though it can be triggered even when ideal plasticity is assumed. This study is concerned mainly with the manner in which the numerical discretization process has to be devised so as to capture the localization phenomenon. In this paper, a method is presented for applying the mixed formulation to study the prediction of localization phenomenon in powder-forming processes. This study is focused on the performance of mixed u − triangular elements to study their e>ciency in indicating localization for various mesh re?nements. An adaptive analysis using element elongation is applied in the modelling of strain localization. The numerical results are obtained for a Von Mises yield criterion applied to a multi-level component, at the ?nal stage of compaction. It is shown that if a correct approximation is used then both the uniformand non-uniformm esh re?nements will converge to the correct answer and clearly indicate the localization phenomenon. It is also observed that an adaptive analysis using element elongation can be eAective in the modelling of such phenomena