Issue
J. Phys. IV France
Volume 08, Number PR8, November 1998
2nd European Mechanics of Materials Conference on Mechanics of Materials with Intrinsic Length Scale : Physics, Experiments, Modelling and Applications
Page(s) Pr8-249 - Pr8-256
DOI https://doi.org/10.1051/jp4:1998831
2nd European Mechanics of Materials Conference on Mechanics of Materials with Intrinsic Length Scale : Physics, Experiments, Modelling and Applications

J. Phys. IV France 08 (1998) Pr8-249-Pr8-256

DOI: 10.1051/jp4:1998831

A 2-D non-local analysis of hydroforming for thin sheets

L.P. Mikkelsen1, 2 and V. Tvergaard2

1  Cambridge University, Engineering Department, Trumpington St., Cambridge CB2 1PZ, U.K.
2  Department of Solid Mechanics, Technical University of Denmark, 2800 Lyngby, Denmark


Abstract
An enhanced membrane theory is used to analyse hydroforming of thin metal sheets. The use of a plane stress or membrane model for such metal forming studies, rather than a full three dimensional numerical analysis, is highly advantageous from the point of view of reducing computer requirements, but the onset and development of localized plastic straining is not realistically predicted. It has been found that a nonlocal formulation of a membrane model, in which a material length is used to represent thickness effects, can give rather accurate predictions of the full 3-D effects. The non-local model implemented here in a hydroforming study is a 2-D version of gradient dependent plasticity theory. The model is used to illustrate the effect of different initial geometries and of different material length parameters.



© EDP Sciences 1998