Paper Title:
Influence of Surface Defect Geometry on the Localization and Failure of AA6111 Sheet: Necking versus Shear
  Abstract

The influence of surface defect geometry on the localization and failure behaviour of AA6111 sheet has been investigated through experimentation and numerical modelling. A series of uniaxial tensile samples were produced with idealized top and bottom surface defects (i.e. grooves), located either symmetrically or asymmetrically on the opposing surfaces. The symmetric arrangement corresponds to the “groove-like” initial imperfection of the classical Marciniak- Kuczyński (M-K) model. Experimental results indicate that both the symmetry of the defects and their wavelength have a profound effect on the resulting mode of localization and failure as well as on the limit strains. Specifically, symmetric surface defects are seen to induce localization and failure through simple necking, whereas asymmetric defects tend to promote macroscopic, throughthickness shearing. Furthermore, asymmetric surface defect geometries are found to produce lower limit strains in the AA6111 sheet under study for defect wavelengths below about 1.5 mm, while the reverse is true when defect wavelengths are above 1.5 mm. Finite element method (FEM) modelling simulations are also presented, demonstrating that the experimentally-observed trends in localization and failure behaviour can be replicated using a mixed isotropic-kinematic hardening implementation of the Gurson-Tvergaard-Needleman (GTN) material model.

  Info
Periodical
Materials Science Forum (Volumes 519-521)
Edited by
W.J. Poole, M.A. Wells and D.J. Lloyd
Pages
131-138
DOI
10.4028/www.scientific.net/MSF.519-521.131
Citation
A.K. Pilkey, C.J. Bayley, M. Györffy, "Influence of Surface Defect Geometry on the Localization and Failure of AA6111 Sheet: Necking versus Shear", Materials Science Forum, Vols. 519-521, pp. 131-138, 2006
Online since
July 2006
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Dong Nyung Lee
Abstract:Asymmetric rolling, in which the circumferential velocities of the upper and lower rolls are different, can give rise to intense ...
1
Authors: Yun Long Chen, Ai Dang Shan, Jian Hua Jiang, Yi Ding
Abstract:Asymmetric rolling has been considered as a possible way to obtain severe plastic deformation (SPD) since it will give an extra shear...
327
Authors: Xiao Mei Li, Yi Ding
Abstract:Asymmetric rolling (ASR) is one of the severe plastic deformation (SPD) processes which are prominently used to reduce grain size and refine...
139
Authors: H.P. Yang, Yu Hui Sha, Fang Zhang, Wei Pei, Liang Zuo
Chapter 6: Materials
Abstract:Through-thickness shear strain variation with speed/radius/friction ratio in cold rolled silicon steel under different asymmetric rolling...
762