Incremental sheet metal forming (ISMF) has demonstrated its great potential to form complex three-dimensional parts without using a component specific tooling. The die-less nature in incremental forming provides a competitive alternative for economically and effectively fabricating low-volume functional sheet parts. However, ISMF has limitations with respect to maximum formable wall angle, geometrical accuracy, and surface finish of the component. In the present work, an experimental study is carried out to study the effect of incremental sheet metal forming process variables on maximum formable angle and surface finish. Box–Behnken method is used to design the experiments for formability study and full factorial method is used for surface finish study. Analysis of experimental results indicates that formability in incremental forming decreases with increase in tool diameter. Formable angle first increases and then decreases with incremental depth and it is also observed that the variation in the formable angle is not significant in the range of incremental depths considered to produce good surface finishes during the present study. A simple analysis model is used to estimate the stress values during incremental sheet metal forming assuming that the deformation occurs predominantly under plane strain condition. A stress-based criterion is used along with the above mentioned analysis to predict the formability in ISMF and its predictions are in very good agreement with the experimental results. Surface roughness decreases with increase in tool diameter for all incremental depths. Surface roughness increases first with increase in incremental depth up to certain angle and then decreases. Surface roughness value decreases with increase in wall angle.

References

References
1.
Jeswiet
,
J.
,
Micari
,
F.
,
Hirt
,
G.
,
Bramley
,
A.
,
Duflou
,
J.
, and
Allwood
,
J.
, 2005, “
Asymmetric Single Point Incremental Forming of Sheet Metal
,”
CIRP Ann.
,
54
(
2
), pp.
623
649
.
2.
Cao
,
J.
,
Huang
,
Y.
,
Reddy
,
N. V.
,
Malhotra
,
R.
, and
Wang
,
Y.
, 2008, “
Incremental Sheet Metal Forming: Advances and Challenges
,” Proceedings of International Conference on Technology of Plasticity (ICTP 2008),
Gyeongju, Korea
.
3.
Allwood
,
J. M.
,
Shouler
,
D. R.
, and
Tekkaya
,
A. E.
, 2007, “
The Increased Forming Limits of Incremental Sheet Forming Processes
,”
Key Eng. Mater.
,
344
, pp.
621
628
.
4.
Silva
,
M. B.
,
Skjoedt
,
M.
,
Atkins
,
A. G.
,
Bay
,
N.
, and
Martins
,
P. A. F.
, 2008, “
Single-Point Incremental Forming and Formability-Failure Diagrams
,”
J. Strain Anal.
,
43
, pp.
15
35
.
5.
Ham
,
M.
, and
Jeswiet
,
J.
, 2006, “
Single Point Incremental Forming and the Forming Criteria for AA3003
,”
CIRP Ann.
,
55
(
1
), pp.
241
244
.
6.
Ham
,
M.
, and
Jeswiet
,
J.
, 2007, “
Single Point Incremental Forming Limits Using a Box-Behnken Design of Experiment
,”
Key Eng. Mater.
,
344
, pp.
629
636
.
7.
Ambrogio
,
G.
,
Duflou
,
J.
,
Filice
,
L.
, and
Aerens
,
R.
, 2007, “
Some Considerations on Force Trends in Incremental Forming of Different Materials
,” Proceeding of 10th ESAFORM Conference, pp.
193
198
.
8.
Filice
,
L.
,
Ambrogio
,
G.
, and
Micari
,
F.
, 2006, “
On-Line Control of Single Point Incremental Forming Operations Though Punch Force Monitoring
,”
CIRP Ann.
,
55
(
1
), pp.
245
248
.
9.
Szekeres
,
A.
,
Ham
,
M.
, and
Jeswiet
,
J.
, 2007, “
Force Measurement in Pyramid Shaped Parts With a Spindle Mounted Force Sensor
,”
Key Eng. Mater.
,
344
, pp.
551
558
.
10.
Bambach
,
M.
,
Todorova
,
M.
, and
Hirt
,
G.
, 2007, “
Experimental and Numerical Analysis of Forming Limits in CNC Incremental Sheet Forming
,”
Key Eng. Mater.
,
344
, pp.
511
518
.
11.
Emmens
,
W. C.
, and
van den Boogaard
,
A. H.
, 2007, “
Strain in Shear and Material Behaviour in Incremental Forming
,”
Key Eng. Mater.
,
344
, pp.
519
526
.
12.
Emmens
,
W. C.
, and
van den Boogaard
,
A. H.
, 2008, “
Tensile Tests With Bending: A Mechanism for Incremental Forming
,” Proceeding of 11th ESAFORM Conference.
13.
Hagen
,
E.
and
Jeswiet
,
J.
, 2004, “
Analysis of Surface Roughness for Parts Formed by CNC Incremental Forming
,”
Proc. Inst. Mech. Eng., Part B
,
219
(
B
), pp.
1
6
.
14.
Ham
,
M.
,
Powers
,
B.
,
Brown
C. A.
,
Jeswiet
,
J.
, and
Hamilton
,
K.
, 2009, “
Roughness Evaluation of Single Point Incrementally Formed Surfaces
,”
Trans. NAMRI/SME
,
37
, pp.
411
418
.
15.
Allwood
,
J. M.
,
Music
,
O.
,
Raithathna
,
A.
, and
Duncan
,
S. R.
, 2009, “
Closed-Loop Feedback Control of Product Properties in Flexible Metal Forming Processes With Mobile Tools
,”
CIRP Ann.
,
58
(
1
), pp.
287
290
.
16.
Malhotra
.
R.
,
Reddy
,
N. V.
, and
Cao
,
J.
, 2010, “
Automatic 3D Spiral Toolpath Generation for Single Point Incremental Forming
,”
ASME J. Manuf. Sci. Eng.
,
132
, pp.
061003
-1–061003-
10
.
17.
Pandey
,
P. M
,
Reddy
,
N. V.
, and
Dhande
S. G.
, 2003, “
Slicing Procedures in Layered Manufacturing
,”
Rapid Prototyping J.
,
9
(
5
), pp.
274
288
.
18.
Verbert
,
J.
,
Belkahhem
,
B.
,
Henrard
,
C.
,
Habraken
,
A. M.
,
Gu
,
J.
,
Sol
,
H.
,
Lauwerf
,
B.
, and
Duflou
,
J. R.
, 2008, “
Multi-Step Tool Path Approach to Overcome Forming Limitations in SPIF
,” Proceedings of ESAFORM 2008, pp.
587
590
.
19.
Skjoedt
,
M.
,
Bay
,
N.
,
Endelt
,
B.
, and
Ingarao
,
G.
, 2008, “
Multi Stage Strategies for Single Point Incremental Forming of a Cup
,”
Int. J. Mater. Form.
,
1
(
Suppl. 1
), pp.
1199
1202
.
20.
Malhotra
,
R.
,
Bhattacharya
,
A.
,
Kumar
,
A.
,
Reddy
,
N. V.
, and
Cao
,
J.
, 2011, “
A New Methodology for Multi-Pass Single Point Incremental Forming With Mixed Toolpaths
,”
CIRP Ann.
,
60
, pp.
323
326
.
21.
Strano
,
M.
, 2005, “
Technological Representation of Forming Limits for Negative Incremental Forming of Thin Aluminum Sheets
,”
J. Manuf. Process.
,
7
(
2
), pp.
122
129
.
22.
Hussain
,
G.
,
Gao
,
L.
,
Hayat
,
N.
, and
Qijian
,
L.
, 2007, “
The Effect of Variation in the Curvature of Part on the Formability in Incremental Forming: An Experimental Investigation
,”
Int. J. Mach. Tools Manuf.
,
47
, pp.
2177
2181
.
23.
Hussain
,
G.
,
Gao
,
L.
, and
Dar
,
N. U.
, 2007, “
An Experimental Study on Some Formability Evaluation Methods in Negative Incremental Forming
,”
J. Mater. Process. Technol.
,
186
, pp.
45
53
.
24.
Hussain
,
G.
,
Dar
,
N. U.
,
Gao
,
L.
, and
Chen
,
M. H.
, 2007, “
A Comparative Study on the Forming Limits of an Aluminum Sheet-Metal in Negative Incremental Forming
,”
J. Mater. Process. Technol.
,
187
, pp.
94
98
.
25.
Nguyen
,
D. T.
,
Park
J. G.
,
Lee
,
H. J.
, and
Kim
,
Y. S.
, 2010, “
Finite Element Method Study of Incremental Sheet Forming for Complex Shape and its Improvement
,”
Proc. Inst. Mech. Eng., Part B
,
224
, pp.
913
924
.
26.
Eyckens
,
P.
,
Vanhove
,
H.
,
Bael
,
A. V.
,
Duflou
,
J. R.
, and
Houtte
,
P. V.
, 2011, “
Tool Directionality in Contour-Based Incremental Sheet Forming: An Experimental Study on Product Properties and Formability
,”
Key Eng. Mater.
,
473
, pp.
897
904
.
27.
Jeswiet
,
J.
,
Hagan
,
A.
, and
Szekeres
,
A.
, 2002, “
Forming Parameters in Incremental Forming of Aluminium Sheet Metal
,”
Proc. Inst. Mech. Eng., Part B
,
216
, pp.
1367
1371
.
28.
Filice
,
L.
,
Fantini
,
L.
, and
Micari
,
F.
, 2002, “
Analysis of Material Formability in Incremental Forming
,”
CIRP Ann.
,
51
, pp.
199
202
.
You do not currently have access to this content.