In this paper, the occurrence of recoil and surface warp during the flat surface-straight edge hemming process is investigated. A general-purpose finite element code ABAQUS/Standard is used to simulate the hemming operations. Reverse bending and springback are the fundamental mechanisms that cause surface warp and recoil. Recoil and warp are not independent. One parameter, final equivalent warp, is used to represent both. Pre-hemming target ending position is proposed based on the minimization of the final equivalent warp. The influence of the geometrical and process parameters on recoil and warp are also discussed.

Issue Section:
Technical Papers
Keywords:
forming processes, finite element analysis, bending, production engineering computing, Hemming, Finite Element Analysis (FEA), Recoil, Surface Warp
Topics:
Warping, Finite element analysis
1.
Zhang
,
G.
,
Hao
,
H.
,
Wu
,
X.
,
Hu
,
S. J.
,
Harper
,
K.
, and
Faitel
,
W.
,
2000
, “
An experimental investigation of curved surface-straight edge hemming
,”
Transactions of NAMARC/SME
,
pp.
311
–
316
.
2.
Hishida, Y., and Sato, Y., 1986, “Analysis of hemming processes by the FEM for improving hemming quality,” 14th IDDRG congress, pp. 21–23.
3.
Niimi, Y., and Hattori, M., 1986, “Development of processing technique for improving hemming quality,” 14th IDDRG congress, pp. 432–433.
4.
Sunaga
,
H.
, and
Makinouchi
,
A.
,
1990
, “
Elastic-plastic FE simulation of sheet metal bending process for auto body panels
,”
Technology of Plasticity
,
3
, pp.
1525
–
1530
.
5.
Umehara
,
Y.
,
1990
, “
Technologies for the more precise press-forming of automobile parts
,”
J. Mater. Process. Technol.
,
22
, No.
3
, pp.
239
–
256
.
6.
ABAQUS/Standard, User’s manual, Vol. 5.6, HKS Inc.
Copyright © 2001
 by ASME
You do not currently have access to this content.