- Volume 24 Issue 5
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Determination of the Forming Limit Strain of Sheet Metals by the Time-dependent Method
시간의존법에 의한 금속판재 성형한계변형률의 결정
Kim, S.G.;Oh, T.H.;Kim, J.D.;Kim, H.J.
- Received : 2015.06.29
- Accepted : 2015.08.31
- Published : 2015.10.01
The forming limit diagram (FLD) is the most commonly used tool for evaluating of sheet metal formability in the manufacturing field as well as the finite element analysis (FEA)-based design process. Determination of the forming limits is considerably influenced by testing/measuring machines, techniques and conditions. These influences may cause a large scatter in FLD from laboratory to laboratory. Scatter is especially true when the ‘position-dependent method’, as is specified in most national and international standards, is used. In the current study a new ‘time-dependent method’ is proposed, which is to determine the forming limit strains more accurately and reasonably when producing a FLD from experimental data. This method is based on continual strain measurement during the test. The results are compared to those from the existing standardized methods.
Time-dependent Method;ISO 12004-2;Forming Limit Strain;Forming Limit Diagram;Nakajima Test