Characterization of materials undergoing severe plastic deformation requires the careful measurement of instantaneous sample dimensions throughout testing. For compressive testing, it is insufficient to simply estimate sample diameter from an easily measured height and volume. Not all materials exhibit incompressibility, and friction during testing can lead to a barreled sample with diameter that varies with height. Video extensometry has the potential to greatly improve testing by capturing the full profile of a sample, allowing researchers to account for such effects. Common two-dimensional (2D) video extensometry algorithms require thin, planar samples, as they are unable to account for out-of-plane deformation. They are, therefore, inappropriate for standard compressive tests which use cylindrical samples that exhibit large degrees of out-of-plane deformation. In this paper, a new approach to 2D video extensometry is proposed. By using background subtraction, the profile of a cylindrical sample can be isolated and measured. Calibration experiments show that the proposed system has a 3.1% error on calculating true yield stress—similar to ASTM standard methods for compressive testing. The system is tested against Aluminum 2024-T351 in a series of cold upsetting tests. The results of these tests match very closely with similar tests from the literature. A preliminary finite element model constructed using data from these tests successfully reproduced experimental results. Diameter data from the finite element model undershot, but otherwise closely matched experimental data.

References

References
1.
Chait
,
R.
, and
Curll
,
C. H.
,
1976
, “
Evaluating Engineering Alloys in Compression
,”
Recent Developments in Mechanical Testing
, ASTM International, West Conshohocken, PA, pp.
3
19
.
2.
Johnson
,
W.
, and
Mellor
,
P. B.
,
1983
,
Engineering Plasticity
,
E.
Horwood
, ed.,
Chichester, UK
.
3.
Chen
,
F.-K.
, and
Chen
,
C.-J.
,
2000
, “
On the Nonuniform Deformation of the Cylinder Compression Test
,”
ASME J. Eng. Mater. Technol.
,
122
(
2
), pp.
192
197
.
4.
Banerjee
,
J. K.
,
1985
, “
Barreling of Solid Cylinders Under Axial Compression
,”
ASME J. Eng. Mater. Technol.
,
107
(
2
), pp.
138
144
.
5.
Bao
,
Y.
,
2003
, “Prediction of Ductile Crack Formation in Uncracked Bodies,”
Ph.D. thesis
, Massachusetts Institute of Technology, Cambridge, MA.
6.
Bao
,
Y.
, and
Wierzbicki
,
T.
,
2004
, “
A Comparative Study on Various Ductile Crack Formation Criteria
,”
ASME J. Eng. Mater. Technol.
,
126
(
3
), pp.
314
324
.
7.
Wierzbicki
,
T.
,
Bao
,
Y.
,
Lee
,
Y. W.
, and
Bai
,
Y.
,
2005
, “
Calibration and Evaluation of Seven Fracture Models
,”
Int. J. Mech. Sci.
,
47
(
4–5
), pp.
719
743
.
8.
Yin
,
F. C. P.
,
Tompkins
,
W. R.
,
Peterson
,
K. L.
, and
Intaglietta
,
M.
,
1972
, “
A Video-Dimension Analyzer
,”
IEEE Trans. Biomed. Eng.
,
BME-19
(
5
), pp.
376
381
.
9.
Gardner
,
R. M.
,
1968
, “Dynamic Aortic Diameter Measurements In Vivo Using Roentgen Videometry,”
Ph.D. thesis
, University of Utah, Salt Lake City, UT.
10.
Sutton, M. A.
, 2013, “
Computer Vision Based, Non-Contacting Deformation and Shape Measurements: A Revolution in Progress
,”
J. S. C. Acad. Sci.
,
11
(1), pp. 11–17.
11.
Wardlow
,
J.
, and
Allameh
,
S.
,
2015
, “On the Micromechanical Characterization of Metallic MEMS by a Hybrid Microtester,”
ASME
Paper No. IMECE2015-50942.
12.
Allameh
,
S. M.
,
Shrotriya
,
P.
,
Butterwick
,
A.
,
Brown
,
S.
,
Yao
,
N.
, and
Soboyejo
,
W.
,
2003
, “
Surface Topography Evolution and Fatigue Fracture of Polysilicon
,”
J. Mater. Sci.
,
38
(
20
), pp.
4145
4155
.
13.
Pan
,
B.
,
Yu
,
L.
,
Wu
,
D.
, and
Tang
,
L.
,
2013
, “
Systematic Errors in Two-Dimensional Digital Image Correlation Due to Lens Distortion
,”
Opt. Lasers Eng.
,
51
(
2
), pp.
140
147
.
14.
Liljenhjerte
,
J.
,
Upadhyaya
,
P.
, and
Kumar
,
S.
,
2016
, “
Hyperelastic Strain Measurements and Constitutive Parameters Identification of 3D Printed Soft Polymers by Image Processing
,”
Addit. Manuf.
,
11
, pp.
40
48
.
15.
Schmid
,
F.
,
Sommer, G.
,
Rappolt, M.
,
Regitnig, P.
,
Holzapfel, G. A.
,
Laggner, P.
, and
Amenitsch, H.
,
2006
, “
Bidirectional Tensile Testing Cell for In Situ Small Angle X-Ray Scattering Investigations of Soft Tissue
,”
Nucl. Instrum. Methods Phys. Res. Sect. B
,
246
(
1
), pp.
262
268
.
16.
G'Sell
,
C.
,
Hiver
,
J.
, and
Dahoun
,
A.
,
2002
, “
Experimental Characterization of Deformation Damage in Solid Polymers Under Tension, and Its Interrelation With Necking
,”
Int. J. Solids Struct.
,
39
(
13–14
), pp.
3857
3872
.
17.
Addiego
,
F.
,
Dahoun
,
A.
,
G'Sell
,
C.
, and
Hiver
,
J.-M.
,
2006
, “
Characterization of Volume Strain at Large Deformation Under Uniaxial Tension in High-Density Polyethylene
,”
Polymer
,
47
(
12
), pp.
4387
4399
.
18.
Sutton
,
M. A.
,
Yan
,
J. H.
,
Tiwari
,
V.
,
Schreier
,
H. W.
, and
Orteu
,
J. J.
,
2008
, “
The Effect of Out-of-Plane Motion on 2D and 3D Digital Image Correlation Measurements
,”
Opt. Lasers Eng.
,
46
(
10
), pp.
746
757
.
19.
Pengxiang Bai
,
X. H.
, and
Zhu
,
F.
,
2015
, “
Optical Extensometer and Elimination of the Effect of Out-of-Plane Motions
,”
Opt. Lasers Eng.
,
65
, pp.
28
37
.
20.
Felipe-Sesé
,
L.
,
Siegmann
,
P.
,
Díaz
,
F. A.
, and
Patterson
,
E. A.
,
2014
, “
Simultaneous In-and-Out-of-Plane Displacement Measurements Using Fringe Projection and Digital Image Correlation
,”
Opt. Lasers Eng.
,
52
, pp.
66
74
.
21.
Siegmann
,
P.
,
Felipe-Sese
,
L.
, and
Diaz-Garrido
,
F.
,
2017
, “
Improved 3D Displacement Measurements Method and Calibration of a Combined Fringe Projection and 2D-DIC System
,”
Opt. Lasers Eng.
,
88
, pp.
255
264
.
22.
Gorji
,
M. B.
, and
Mohr
,
D.
,
2017
, “
Micro-Tension and Micro-Shear Experiments to Characterize Stress-State Dependent Ductile Fracture
,”
Acta Mater.
,
131
, pp.
65
76
.
23.
Chen
,
F.
,
Chen
,
X.
,
Xie
,
X.
,
Feng
,
X.
, and
Yang
,
L.
,
2013
, “
Full-Field 3D Measurement Using Multi-Camera Digital Image Correlation System
,”
Opt. Lasers Eng.
,
51
(
9
), pp.
1044
1052
.
24.
Genovese
,
K.
,
Casaletto
,
L.
,
Rayas
,
J. A.
,
Flores
,
V.
, and
Martinez
,
A.
,
2013
, “
Stereo-Digital Image Correlation (DIC) Measurements With a Single Camera Using a Biprism
,”
Opt. Lasers Eng.
,
51
(
3
), pp.
279
285
.
25.
Wang
,
R.
,
Li
,
X.
, and
Zhang
,
Y.
,
2008
, “
Analysis and Optimization of the Stereo-System With a Four-Mirror Adapter
,”
J. Eur. Opt. Soc.
,
3
, p.
08033
.
26.
Genovese
,
K.
,
Cortese
,
L.
,
Rossi
,
M.
, and
Amodio
,
D.
,
2016
, “
A 360-Deg Digital Image Correlation System for Materials Testing
,”
Opt. Lasers Eng.
,
82
, pp.
127
134
.
27.
ASTM
,
2009
, “Standard Test Methods of Compression Testing of Metallic Materials at Room Temperature,” ASTM International, West Conshohocken, PA, Standard No.
ATSM E9-09
.
28.
Khan
,
A. S.
, and
Liu
,
H.
,
2012
, “
A New Approach for Ductile Fracture Prediction on Al 2024-T351 Alloy
,”
Int. J. Plast.
,
35
, pp.
1
12
.
29.
Seidt
,
J. D.
, and
Gilat
,
A.
,
2013
, “
Plastic Deformation of 2024-T351 Aluminum Plate Over a Wide Range of Loading Conditions
,”
Int. J. Solids Struct.
,
50
(
10
), pp.
1781
1790
.
30.
Piccardi
,
M.
,
2004
, “
Background Subtraction Techniques: A Review
,”
IEEE
International Conference on Systems, Man, and Cybernetics, Hague, The Netherlands, Oct. 10–13, pp.
3099
3104
.
31.
Hallquist
,
J.
,
2006
, “LS-DYNA® Theory Manual,” Livermore Software Technology Corporation, Livermore, CA.
32.
Matweb
,
2016
, “
Alclad Aluminum 2024-T4, T351
,” MatWeb, LLC, Blacksburg, VA, accessed, Feb. 9, 2016, http://www.matweb.com/search/DataSheet.aspx?MatGUID=7c5d44902e31417f967848c8454cc516
33.
Male
,
A. T.
, and
Cockcroft
,
M. G.
,
1964
, “
Coefficient of Friction Under Conditions of Bulk Plastic Deformation
,”
J. Inst. Met.
,
64
(
93
), pp.
38
46
.
34.
Sofuoglu
,
H.
, and
Rasty
,
J.
,
1999
, “
On the Measurement of Friction Coefficient Utilizing the Ring Compression Test
,”
Tribol. Int.
,
32
(
6
), pp.
327
335
.
35.
Instron
,
2013
, “
Industrial Series RD Models Manual, 4.0713
,”
Instron International
, Norwood, MA.
You do not currently have access to this content.