Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/157991

Title

A new analytical theory for earing generated from anisotropic plasticity

Author(s)

Yoon, J. W.;  Dick, R. E.;  Barlat, F.

Abstract

Commercial canmaking processes include drawing, redrawing and several ironing operations. It is experimentally observed that during the drawing and redrawing processes earing develops, but during the ironing processes earing is reduced. It is essential to understand the earing mechanism during drawing and ironing for an advanced material modeling. A new analytical approach that relates the earing profile to r-value and yield stress directionalities is presented in this work. The analytical formula is based on the exact integration of the logarithmic strain. The derivation is for a cylindrical cup under the plane stress condition based on rigid perfect plasticity while force equilibrium is not considered. The earing profile is obtained solely from anisotropic plastic properties in simple tension. The earing mechanism is explained from the present theory with explicit formulae. It has been proved that earing is the combination of the contributions from r-value and yield stress directionalities. From a directionality (y-axis) vs. angle from the rolling (x-axis) plot, the earing profile is generated to be a scaled mirror image of the r-value directionality with respect to 90° (x = 90) and also a scaled mirror image of the yield stress directionality with respect to the reference yield stress (y = 1). Three different materials (Al–5% Mg alloy, AA 2090-T3 and AA 3104 RPDT control coil) are considered for verification purposes. This approach provides a fundamental basis for understanding the earing mechanism. In practice, the present theory is also very useful for the prediction of the earing profile of a drawn and iron cup and its related convolute cut-edge design for an earless cup.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Engineering and Industrial Sciences

Source

International Journal of Plasticity, Vol. 27, no. 8 (Aug 2011), pp. 1165-1184

Publication year

2011

FOR Code(s)

0905 Civil Engineering;  0912 Materials Engineering;  0913 Mechanical Engineering

Keyword(s)

Analytical approach;  Cup height profile;  Earing;  r-Value;  Yield stress

Publisher

Elsevier

ISSN

0749-6419

Publisher URL

http://dx.doi.org/10.1016/j.ijplas.2011.01.002

Copyright

Copyright © 2011 Elsevier Ltd. All rights reserved.

Peer reviewed