Influence of strain-rate sensitivity on necking and instability in sheet metal forming

Authors
Citation
My. Li et A. Chandra, Influence of strain-rate sensitivity on necking and instability in sheet metal forming, J MATER PR, 96(1-3), 1999, pp. 133-138
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science & Engineering
Journal title
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
ISSN journal
0924-0136 → ACNP
Volume
96
Issue
1-3
Year of publication
1999
Pages
133 - 138
Database
ISI
SICI code
0924-0136(19991101)96:1-3<133:IOSSON>2.0.ZU;2-2
Abstract
Analytical closed form solutions based on a linear perturbation analysis ar e obtained to predict limit strains for rate sensitive materials. A closed form solution, independent of the choice of yield criterion, is first obtai ned for the negative minor strain regime of the forming limit diagram (FLD) . The Von Mises yield criterion is invoked next, and the limit strains corr esponding to the positive minor strain regime of the FLD are obtained. Pred ictions from the analytical model are then compared to experimental observa tions. It is noted that the effective limit strain is enhanced by strain ra te sensitivity of the material. It is also observed that the effective limi t strain is not influenced by the prior strain path, but rather by the inst antaneous strain rate ratio in the final stage of the quasi-stable deformat ion. (C) 1999 Elsevier Science S.A. All rights reserved.