Forming Limit during Superglatic Deformation of Sheet Metals

Du Zhixiao; Li Miaoquan; Liu Mabao; Wu Shichun

Article Contents

Article Navigation > Applied Mathematics and Mechanics > 1996 > 17(2): 127-132

Du Zhixiao, Li Miaoquan, Liu Mabao, Wu Shichun. Forming Limit during Superglatic Deformation of Sheet Metals[J]. Applied Mathematics and Mechanics, 1996, 17(2): 127-132.

Citation:

Du Zhixiao, Li Miaoquan, Liu Mabao, Wu Shichun. Forming Limit during Superglatic Deformation of Sheet Metals[J]. Applied Mathematics and Mechanics, 1996, 17(2): 127-132.

Citation:

Du Zhixiao, Li Miaoquan, Liu Mabao, Wu Shichun. Forming Limit during Superglatic Deformation of Sheet Metals[J]. Applied Mathematics and Mechanics, 1996, 17(2): 127-132.

PDF( 374 KB)

Forming Limit during Superglatic Deformation of Sheet Metals

Faculty 402 of Northwestern Polytechnical University, Xi'an 710072, P. R. China

Received Date: 1994-10-24
Rev Recd Date: 1995-03-07
Publish Date: 1996-02-15

Abstract

Abstract

In the present paper, a thermo-viscoplastic damage potential and Hill's normal anisolropy(isotropy in plane).yield criterion to be quadratic in the stress components are combined to describe the interaction process of damage and instability during superplastic deformation, based on the kinetic equation for damoge during superplastic deformation and the deformation features of superplastic materials. The superplastic deformation process is devided into four Slages, namely, Stable, quasistable, Strain path drift to plane Strain and piane strain stages, and a damageinstability model during superplastic deformation of sheet metals is developed through numerical method. On the basis of the above results and taking the occurrence of localized inslability(dε₂=0) or the cavity volume fraction reaching the critical value(f_c) as a fracture criterion. the forming limit during superplastic deformation of sheet metals is predicted.
- superplasticity,
- damage-intability,
- forming limit

FullText(HTML)

References(10)

References

[1]	林兆荣,《金属超塑性成形原理与实用》航空工业出版社,北京(1990).
[2]	K.S,Chan,D.A.Koss and A.K,Ghosh,Localized necking'of sheet at negative minor strains,Met.Traps.A,15(1984),323-329.
[3]	J.Lian and B,Bandelet,Forming limit diagram of sheet metal in the negative minor strain region,Mat.Sci.dnd Eng.,as,(1987),137-144.
[4]	Z.Marciniak and K.Kuczynski,Limit strains in process of strech-forming sheet metal,Int,J.Mech.Sci,9(1967),609-620.
[5]	M,H,A,Nawaz,Forming limit diagrams and damage in mild steel,J,Mat,Sef,Letters,13(1978),1142-1145
[6]	杜志孝、李森泉、吴诗J淳,损伤对LY12CZ铝合金和H62黄铜板料超塑性可成形性的影响,西北工业大学学报,13(2)(1995),323-324.
[7]	D.Zhou and J.Lian,Numerical analysis of superplastic bulging for cavity-sensitive materials,Int,J,Mech,Sci.,29(8)(1987),565-576.
[8]	J.R.Rice and D,M,Tracey,On the ductile enlargement of voids in triaxial stress field,J,Mech.Phys,Solids,17(1969),201-217.
[9]	Du Zhixiao and Wu Shichun,A kinetic equation for damage during sup.J plastic deformation,J,Mater.Process,Technol,52(2-1)(1935),270-279.
[10]	W,A,Spitzig,R.E,Smelser and O.Richmond,The evolution of damage and fracture in iron compacts with various initial porosities,Acta Metall.,36(5)(1988).1201-1211.