A Numerical Analysis of Thickness Effects on Limit Strains in Metal Sheets
Numerical simulations of the plane-strain tension test and of the Nakazima test
have been carried out with the aim of evaluating the influence of the sheet thickness upon the
strain localisation process. It is shown that the limit strains obtained with the usual
experimental methods are increasing functions of the thickness, as a result of the larger
spread of short-range strain gradients for thicker sheets. When the same tooling geometry is
employed with sheets of different thicknesses, the intrinsic thickness dependence of limit
strains should thus be analysed in relation with a numerical evaluation of the strain gradients developed during the test.
Luciano Pessanha MOREIRA, Gérard FERRON, Marion MARTINY
sheet forming, limit strains, thickness effects, finite element modelling.