This study is focused on the description of ductile fracture initiation, which is needed to predict product shapes in the blanking process. Two approaches are elaborated using a local ductile fracture model. According to literature, characterization of such a model should take place under loading conditions, comparable to the application. Therefore, the first approach incorporates the characterization of a ductile fracture model in a blanking experiment. The second approach is more favorable for industry. In this approach a tensile test is used to characterize the fracture model, instead of a complex and elaborate blanking experiment. Finite element simulations and blanking experiments are performed for five different clearances to validate both approaches. In conclusion it can be stated that for the investigated material, the first approach gives very good results within the experimental error. The second approach, the more favorable one for industry, yields results within 6 percent of the experiments over a wide, industrial range of clearances, when a newly proposed criterion is used. [S1087-1357(00)02202-4]
Issue Section:
Technical Papers
1.
Chang
, T.
, and Swift
, H.
, 1950
, “Shearing of Metal Bars
,” J. Inst. Met.
, 78
, pp. 119
–146
.2.
Atkins
, A.
, 1981
, “Surfaces Produced by Guillotining
,” Philos. Mag.
, 43
, pp. 627
–641
.3.
Chang
, T.
, 1951
, “Shearing of Metal Blanks
,” J. Inst. Met.
, 78
, pp. 393
–414
.4.
Johnson, W., and Slater, R., 1967, “A Survey of the Slow and Fast Blanking of Metals at Ambient and High Temperatures,” Proceedings of the International Conference of Manufacturing Technology, Michigan, pp. 773–851.
5.
Choy, C., and Balendra, R., 1996, “Experimental Analysis of Parameters Influencing Sheared-Edge Profiles,” Proceedings of the 4th International Conference on Sheet Metal, Twente, pp. 101–110.
6.
Noble
, C.
, and Oxley
, P.
, 1963
, “Crack Formation in Blanking and Piercing
,” Int. J. Prod. Res.
, 2
, pp. 265
–274
.7.
Fukui
, S.
, Konda
, K.
, and Maeda
, K.
, 1971
, “Smooth Shearing by Stepped Profile Tool
,” Ann. CIRP
, 20
, pp. 57
–58
.8.
Zhou
, Q.
, and Wierzbicki
, T.
, 1996
, “A Tension Zone Model of Blanking and Tearing of Ductile Metal Plates
,” Int. J. Mech. Sci.
, 38
, pp. 303
–324
.9.
Post, J., and Voncken, R., 1996, FEM analysis of the punching process, Proceedings of the 4th International Conference on Sheet Metal, Twente, pp. 159–169.
10.
Taupin
, E.
, Breitling
, J.
, Wu
, W.-T.
, and Altan
, T.
, 1996
, “Materials Fracture and Burr Formation in Blanking; Results of FEM Simulations and Comparison with Experiments
,” J. Mater. Process. Technol.
, 59
, pp. 68
–78
.11.
Brokken
, D.
, Brekelmans
, W.
, and Baaijens
, F.
, 1998
, “Numerical Modelling of the Metal Blanking Process
,” J. Mater. Process. Technol.
, 83
, pp. 192
–199
.12.
Broek, D., 1971, A study on ductile failure, Ph.D. thesis, Delft University of Technology, The Netherlands.
13.
Dodd, B., and Bai, Y., 1987, Ductile Fracture and Ductility—With Applications to Metalworking, Academic Press, London.
14.
Bolt, P. J., 1989, Prediction of ductile failure, Ph.D. thesis, Eindhoven University of Technology, The Netherlands.
15.
Clift
, S.
, Hartley
, P.
, Sturgess
, C.
, and Rowe
, G.
, 1990
, “Fracture Prediction in Plastic Deformation Processes
,” Int. J. Mech. Sci.
, 32
, pp. 1
–17
.16.
Swinden
, T.
, and Bolsover
, G.
, 1927
, “Some Notes on Cold-Rolled Strip Steel
,” J. Iron Steel Inst., London
, 115
, pp. 569
–602
.17.
Brokken, D., Goijaerts, A., Brekelmans, W., Oomens, C., and Baaijens, F., 1997, “Modeling of the Blanking Process,” Computational Plasticity, Fundamentals and Applications, Vol. 2, Barcelona, pp. 1417–1424.
18.
Stegeman
, Y.
, Goijaerts
, A.
, Brokken
, D.
, Brekelmans
, W.
, Govaert
, L.
, and Baaijens
, F.
, 1999
, “An Experimental and Numerical Study of a Planar Blanking Process
,” J. Mater. Process. Technol.
, 87
, pp. 266
–276
.19.
MARC, 1998, MARC Manual: Volume A, User Information, pp. A5.16–A6.40.
20.
Schreurs
, P.
, Veldpaus
, F.
, and Brekelmans
, W.
, 1986
, “Simulation of Forming Processes Using the Arbitrary Eulerian-Lagrangian Formulation
,” Comput. Methods Appl. Mech. Eng.
, 58
, pp. 19
–36
.21.
Hue´tink
, J.
, Vreede
, P.
, and van der Lugt
, J.
, 1990
, “Progress in Mixed Eulerian-Lagrangian Finite Element Simulation of Forming Processes
,” Int. J. Numer. Methods Eng.
, 30
, pp. 1441
–1457
.22.
Goijaerts, A., Stegeman, Y., Govaert, L., Brokken, D., Brekelmans, W., and Baaijens, F., 1998, “A validated fem model to improve metal blanking,” Simulation of Materials Processing: Theory, Methods and Applications, Twente, pp. 979–984.
23.
Freudenthal, A. M., 1950, The Inelastic Behavior of Solids, Wiley, New York.
24.
Cockroft
, M. G.
, and Latham
, D. J.
, 1968
, “Ductility and the Workability of Metals
,” J. Inst. Met.
, 96
, pp. 33
–39
.25.
Jeong, S., Kang, J., and Oh, S., 1996, “A Study on Shearing Mechanism by FEM Simulation,” Advanced Technology of Plasticity, Columbus, Ohio, USA, pp. 631–634.
26.
Klocke, F., and Sweeney, K., 1998, “Crack Prediction and Prevention in the Fine Blanking Process: FEM Simulations and Experimental Results,” Proceedings of the International Conference on Sheet Metal Forming, Twente, pp. 215–222.
27.
Faura
, F.
, Garcia
, A.
, and Estrems
, M.
, 1998
, “Finite Element Analysis of Optimum Clearance in the Blanking Process
,” J. Mater. Process. Technol.
, 80–81
, pp. 121
–125
.28.
Oyane
, M.
, Sato
, T.
, Okimoto
, K.
, and Shima
, S.
, 1980
, “Criteria for ductile fracture and their applications
,” J. Mech. Work. Technol.
, 4
, pp. 65
–81
.29.
Rice
, J. R.
, and Tracey
, D. M.
, 1969
, “On the Ductile Enlargement of Voids in Triaxial Stress Fields
,” J. Mech. Phys. Solids
, 17
, pp. 201
–217
.30.
Goijaerts, A. M., Govaert, L. E., and Baaijens, F. P. T., 2000, “Evaluation of Ductile Fracture Models for Different Metals in Blanking,” submitted to J. Mater. Process. Technol.
31.
Goijaerts, A. M., Govaert, L. E., and Baaijens, F. P. T., 2000, “Experimental and Numerical Investigation on the Influence of Process Speed on the Blanking Process,” submitted to J. Manufacturing Science and Engineering Transactions.
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