Determination of optimal shapes for the stampings of arbitra(6)

H.Shim/JournalofMaterialsProcessingTechnology121(2002)116±122121

Fig.11.Evolutionofoptimalblankdesignstages:(a)initialshape(Numisheet'99);(b)2nddesign;(c)3rddesign(optimal

blank).

Acknowledgements

ThisworkwassupportedbytheBrainKorea21Project.References

parisonofdeformedshapeforNumisheet'99benchmark:(a)Numisheet'99benchmarkblank;(b)optimalblank.

[1]H.Gloeckl,nge,Computeraideddesignofblanksfordeep

drawnirregularshapedcomponents,in:Proceedingsofthe11thNAMRC,1983,pp.243±251.

[2]J.H.Vogel,D.Lee,Ananalyticalmethodfordeepdrawingprocess

design,Int.J.Mech.Sci.32(11)(1990)891±907.

[3]X.Chen,R.Sowerby,Thedevelopmentofidealblankshapesbythe

methodofplanestresscharacteristics,Int.J.Mech.Sci.2(1992)159±166.

[4]X.Chen,R.Sowerby,Blankdevelopmentandthepredictionof

earingincupdrawing,Int.J.Mech.Sci.8(5)(1996)509±516.[5]T.Kuwabara,W.H.Si,PC-basedblankdesignsystemfordeep-drawingirregularlyshapedprismaticshellswitharbitrarilyshapedflange,J.Mater.Proc.Technol.63(1997)89±94.

[6]R.Sowerby,J.L.Duncan,E.Chu,Themodelingofsheetmetal

stampings,Int.J.Mech.Sci.28(7)(1986)415±430.

[7]G.N.Blount,B.V.Fischer,Computerizedblankshapepredictionfor

sheetmetalcomponentshavingdoubly-curvedsurfaces,Int.J.Prod.Res.33(4)(1995)993±1005.

[8]C.H.Toh,S.Kobayashi,Deformationanalysisandblankdesignin

squarecupdrawing,Int.J.Mech.Sci.25(1)(1985)

15±32.

4.Conclusion

Asystematicmethodofoptimalblankdesignbasedonthesensitivityanalysishasbeenappliedtothedrawingsofarbitraryshape.Fromtheresultofdeformationprocessanalysis,shapesensitivityhasbeenobtainednumerically.Withtheshapesensitivity,initialblankhasbeenmodi®edinordertoobtainthedesiredshape.Thenumericalandexperi-mentalresultsdemonstratethatthepresentmethodprovidesexcellentpredictionofblankshapeandtheblankshapegivesthetargetshapealmostexactly.Throughtheinvestigationtheproposedsystematicmethodofoptimalblankdesignisfoundtobeveryeffective.