ISSN: 1945-7553
CODEN: JTEVAB
Published Online: 11 December 2012
Page Count: 12

Detailed Investigation of Forming Limit Determination Standards for Aluminum Alloys

Dilmec, Murat
Dept. of Mechanical Engineering, Faculty of Architecture and Engineering, Selcuk Univ., Konya,

Halkaci, H. Selcuk
Dept. of Mechanical Engineering, Faculty of Architecture and Engineering, Selcuk Univ., Konya,

Ozturk, Fahrettin
Dept. of Mechanical Engineering, Faculty of Engineering, Nigde Univ., Nigde,
Dept. of Mechanical Engineering, The Petroleum Institute, Abu Dhabi,

Turkoz, Mevlut
Dept. of Mechanical Engineering, Faculty of Seydisehir Eng., Selcuk Univ., Seydisehir, Konya,

(Received 26 September 2011; accepted 16 May 2012)

Abstract

In this study, experimental studies were conducted to evaluate the differences between the ASTM E2218-02 and ISO 12004-2 standards that are used for construction of the forming limit curve (FLC) and that made various assumptions, which create dissimilar FLCs for the same material. The comparison was made for two materials which have moderate brittle and ductile characteristics, AA2024-T4 and AA5754-O alloys, respectively. The effects of a specimen’s geometry, lubrication condition, and determination methods of limit strains on FLCs were considered and compared. Because the same strain evaluation method should be used for the standards, so as to be able to investigate the effect of only standards, a simple method in the computer grid analysis system was used. To test the validity and the reliability of the method, limit strains on the same specimens were also determined with using a real-time measurement method for the ISO experiments, and the results reveal that the method is reliable. Failure mechanisms were inspected for further investigation. The Nakajima specimens formed with the two standards showed different failure mechanisms. Finally, conducting the case studies, it was concluded that ISO 12004-2 yields more reliable and reproducible results than the ASTM standard.

Keywords:
ASTM E2218-02, ISO 12004-2, forming limit curve, failure

Paper ID: JTE104356
DOI: 10.1520/JTE104356
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