Characterization of initial anisotropy of sheet metals employing inhomogeneous strain fields

Alper Güner*, Celal Soyarslan, Alexander Brosius, A. Erman Tekkaya

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

Abstract

The realistic finite element simulation of sheet metal forming processes necessitates the accurate characterization of plastic behavior of the sheet. For this purpose different experiments and specimen geometries are used in the field of sheet metal characterization to supply information to the increasing number of sophisticated constitutive models demanding many parameters. This work proposes an inverse procedure that reduces the number of needed experiments by utilizing the distribution of strains in the identification of the initial yield locus of sheet metals. The procedure includes the optical measurement of strains on a flat specimen with a varying cross-section. The geometry of the specimen allows obtaining a distribution of strains rather than a uniform deformation. The measured deformation field is compared with the numerical results which use the YLD2000-2D yield criterion and the difference is tried to be minimized in an inverse framework using the Levenberg-Marquardt algorithm. The proposed method is applied to the commercial aluminum alloy AA6016 by varying the specimen orientation with respect to the rolling direction. The results show that the use of the strain distribution in the objective function is a crucial point in identification of the yield locus. The inversely obtained yield loci are in accordance with the conventionally obtained yield stresses and r-values and it is showed that the proposed specimen and the method can successfully characterize the initial anisotropy of the sheet metals in the first quadrant by using one tensile experiment and one layer compression test.

Original languageEnglish
Title of host publication8th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes, NUMISHEET 2011
Pages750-757
Number of pages8
DOIs
Publication statusPublished - 2011
Externally publishedYes
Event8th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes, NUMISHEET 2011 - Seoul, Korea, Republic of
Duration: 21 Aug 201126 Aug 2011
Conference number: 8

Publication series

NameAIP Conference Proceedings
Volume1383
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Conference

Conference8th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes, NUMISHEET 2011
Abbreviated titleNUMISHEET 2011
Country/TerritoryKorea, Republic of
CitySeoul
Period21/08/1126/08/11

Keywords

  • Finite element
  • Inverse method
  • Sheet metal
  • Yield locus

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