An Experimental and Numerical Study of Forming Limit Diagram of Low Carbon Steel Sheets

Subject Areas : Engineering

M Kadkhodayan ¹ , H Aleyasin ²

1 - Department of Mechanical Engineering ,Islamic Azad University, Mashhad Branch
2 - Department of Mechanical Engineering ,Islamic Azad University, Mashhad Branch

Received: 2015-02-18 Accepted : 2015-04-05 Published : 2015-06-30

Keywords: Finite Element, Forming Limit Diagram, Out-of-plane, Localized necking,

Abstract :

The forming limit diagram (FLD) is probably the most common representation of sheet metal formability and can be defined as the locus of the principal planar strains where failure is most likely to occur. Low carbon steel sheets have many applications in industries, especially in automotive parts, therefore it is necessary to study the formability of these steel sheets. In this paper, FLDs, were determined experimentally for two grades of low carbon steel sheets using out-of-plane (dome) formability test. The effect of different parameters such as work hardening exponent (n), anisotropy (r) and thickness on these diagrams were studied. In addition, the out-of-plane stretching test with hemispherical punch was simulated by finite element software Abaqus. The limit strains occurred with localized necking were specified by tracing the thickness strain and its first and second derivatives versus time at the thinnest element. Good agreement was achieved between the predicted data and the experimental data.

References:

[1] Brun R., Chambard A., Lai M., De Luca P., 1999, Actual and virtual testing techniques for a numerical definition of materials, Numisheet 99.
[2] Cao J., Yao H., Karafillis A., Boyce M.C., 2000, Prediction of localized thinning in sheet metal using a general anisotropic yield criterion, International Journal of Plasticity 16: 1105-1129.
[3] Clift S.E., Hartley P., Sturgess C.E.N., Rowe G.W., 1990, Fracture prediction in plastic deformation processes, International Journal of Mechanical Sciences 32: 1-17.
[4] Friedman P.A., Pan J., 2000, Effects of plastic anisotropy and yield criteria on prediction of forming limit curves, International Journal of Mechanical Sciences 42: 29-48.
[5] Geiger M., Merklein M., 2003, Determination of forming limit diagrams- a new analysis method for characterization of materials formability, Annals of the CIRP 52: 213-216.
[6] Goodwin G.M., 1968, Application of strain analysis to sheet metal forming problems in the press shop, SAE Technical Paper 680093, doi:10.4271/680093.
[7] Hecker S.S., 1975, Simple technique for determining forming limit curves, Sheetmetal Industries Ltd 52: 671-676.
[8] Hill R., 1948, A theory of yielding and plastic flow of anisotropic metals, Proceedings A 193: 281-297.
[9] Huang H.M., Pan J., Tang S.C., 2000, Failure prediction in anisotropic sheet metals under forming operations with consideration of rotating principal stretch directions, International Journal of Plasticity 16: 611-633.
[10] Marciniak Z., Kuczynski K., 1967, Limit strains in the processes of stretch forming sheet metal, International Journal of Mechanical Sciences 9: 609-620.
[11] Narayanasamy R., Sathiya Narayanan C., 2006, Forming limit diagram for Indian interstitial free steels, Materials & Design Journal 27: 882-899.
[12] Ozturk F., Lee D., 2004, Analysis of forming limits using ductile fracture criteria, Journal of Materials Processing Technology 147: 397-404.
[13] Pepelnjak T., Petek A., Kuzman K., 2005, Analysis of the forming limit diagram in digital environment, Advanced Material Research 6/8: 697-704.
[14] Petek A., Pepelnjak T., Kuzman K., 2005, An improved method for determining a forming limit diagram in the digital environment, Journal of Mechanical Engineering 51: 330-345.
[15] Raghavan K.S., 1995, A simple technique to generate in-plane forming limit curves and selected applications, Metallurgical and Materials Transactions A 26(8): 2075-2084.
[16] Takuda H., Mori K., Takakura N., Yamaguchi K., 2000, Finite element analysis of limit strains in biaxial stretching of sheet metals allowing for ductile fracture, International Journal of Mechanical Sciences 42: 785-798.
[17] Wu P.D., Jain M., Savoie J., MacEwen S.R., Tugcu P, Neale K.W., 2003, Evaluation of anisotropic yield functions for aluminum sheets, International Journal of Plasticity 19: 121-138.
[18] Yoshida T., Katayama T., Usuda M., 1995, Forming-limit analysis of hemispherical-punch stretching using the three-dimensional finite element method, Journal of Materials Processing Technology 50: 226-237.