Determination of Measurement Uncertainty in Extracting of Forming Limit Diagrams

Authors: M. Mahboubkhah, H. Fayazfar

Abstract:

In this research, Forming Limit Diagrams for supertension sheet metals which are using in automobile industry have been obtained. The exerted strains to sheet metals have been measured with four different methods and the errors of each method have also been represented. These methods have been compared with together and the most efficient and economic way of extracting of the exerted strains to sheet metals has been introduced. In this paper total error and uncertainty of FLD extraction procedures have been derived. Determination of the measurement uncertainty in extracting of FLD has a great importance in design and analysis of the sheet metal forming process.

Keywords: Forming Limit Diagram, Major and Minor Strain, Measurement Uncertainty.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1082889

References:

[1] G. E. Diter, Workability testing techniques, American society for metals, 1984.
[2] S. P. Keeler, "Determination of Forming Limits Automotive Stamping," Sheet Met.Ind. Vol 42, 1965, pp. 683-691.
[3] E. J. Obermeyer, S. A. Majlessi, "A review of recent advances in the application of blank-holder force towards improving the forming limits of sheet metal parts," Journal of Materials Processing Technology, Vol. 75, 1998, pp. 222-234.
[4] S. L. Semiatin, and J. J. Jonas, "Formability and workability of metals", LOP publishing Ltd., 1991
[5] R. M. Caddel, W. F. Hasford, Metal forming Mechanics and Metallurgy, Prentice-Hall, Inc., Englewoods Cliffs, NJ, 1993.
[6] D. W. Manthey, D. Lee, R. M. Pearce and N. Y. Troy, "The need for surface strain measurement", Metal Forming Magazine, 2007.
[7] Standard Test Method for Determining Forming Limit Curves, ASTM E2218 - 02, Vol. 3, no. 1, 2008.