Two models for predicting the stress-strain curve of porous NiTi under compressive loading are presented in this paper. Porous NiTi shape memory alloy is considered as a composite composed of solid NiTi as matrix and pores as inclusions. Eshelby’s equivalent inclusion method and Mori-Tanaka’s mean-field theory are employed in both models. Two types of pore connectivity are investigated. One is closed cells (model 1); the other is where the pores are interconnected to each other forming an open-cell microstructure (model 2). We also consider two different shapes of pores, spherical and ellipsoidal. The stress-strain curves of porous shape memory alloy with spherical pores and ellipsoidal pores are compared. It is found that the ellipsoidal shape assumption is more reasonable than the assumption of spherical pores. Comparison of the stress-strain curves of the two models shows that use of open-cell microstructure (model-2) makes the predictions more agreeable to the experimental results of porous NiTi whose microstructure exhibits open-cell microstructure.

1.
Lagoudas
,
D. C.
,
Strelec
,
J. K.
,
Yen
,
J.
, and
Khan
,
M. A.
, 2001, “
Intelligent Design Optimization of a Shape-Memory-Alloy-Actuated Reconfigurable Wing
,”
Proc. SPIE
0277-786X,
3984
, pp.
338
348
.
2.
Garner
,
L. N.
,
Wilson
,
L. J.
,
Lagoudas
,
D. C.
, and
Rediniotis
,
O. K.
, 2000, “
Development of a Shape Memory Alloy Actuated Biomimetic Vehicle
,”
Smart Mater. Struct.
0964-1726,
9
, pp.
673
683
.
3.
Martynova
,
I.
,
Skorohod
,
V.
, and
Solonin
,
S.
, 1991, “
Shape Memory and Superelasticity Behavior of Porous Ti-Ni Material
,”
J. Phys. IV
1155-4339,
1991
, pp.
C4/421
C4/426
.
4.
Goncharuk
,
N. V.
,
Martynova
,
I.
,
Naidenova
,
I. F.
, and
Skorokhod
,
O. R.
, 1992, “
Superelaticity and Shape Memory of Sintered Porous Titanium Nickelide
,”
Poroshk. Metall. (Kiev)
0032-4795,
4
, pp.
56
60
.
5.
Li
,
Y. H.
,
Rong
,
L. J.
, and
Li
,
Y. Y.
, 1998, “
Porous NiTi Alloy Prepared From Elemental Powder Sintering
,”
J. Mater. Res.
0884-2914,
13
, pp.
2847
2851
.
6.
Li
,
Y. H.
,
Rong
,
L. J.
,
Luo
,
X. H.
, and
Li
,
Y. Y.
, 2000, “
Microstructure and Superelaticity of Porous NiTi Alloy
,”
Sci. China, Ser. E: Technol. Sci.
1006-9321,
E-42
, pp.
94
1010
..
7.
Li
,
B. Y.
,
Rong
,
L. J.
, and
Li
,
Y. Y.
, 1998, “
Transformation Behavior of Sintered Porous NiTi Alloys
,”
Metall. Mater. Trans. A
1073-5623,
30A
, pp.
2753
2756
.
8.
Yuan
,
B.
,
Chung
,
C. Y.
, and
Zhu
,
M.
, 2004, “
Microstructure and Martensitic Transformation Behavior of Porous NiTi Shape Memory Alloy Prepared by Hot Isostaic Pressing Processing
,”
Mater. Sci. Eng., A
0921-5093,
382
, pp.
181
187
.
9.
Li
,
B. Y.
,
Rong
,
L. J.
,
Gjuanter
,
V. E.
, and
Li
,
Y. Y.
, 2000, “
Porous NiTI Shape Memory Alloys Produced by Two Different Methods
,”
Z. Metallkd.
0044-3093,
91
, pp.
291
295
.
10.
Lagoudas
,
D. C.
,
Entchev
,
P. B.
, and
Vandygriff
,
E. C.
, 2000, “
Modeling of Thermomehcanical Response of Porous Shape Memory Alloys
,”
Proc. SPIE
0277-786X,
3992
, pp.
141
153
.
11.
Zhao
,
Y.
,
Taya
,
M.
,
Kang
,
Y. S.
, and
Kawasaki
,
A.
, 2005, “
Compressive Behavior of Porous NiTi Shape Memory Alloy
,”
Acta Mater.
1359-6454,
53
(
2
), pp.
337
343
.
12.
Eshelby
,
J. D.
, 1957, “
The Determination of the Elastic Field of an Ellipsoidal Inclusion, and Related Problems
,”
Proc. R. Soc. London, Ser. A
1364-5021,
3
, pp.
376
396
.
13.
Tanaka
,
K.
, and
Mori
,
T.
, 1973, “
Average Stress in Matrix and Average Elastic Energy of Materials With Misfitting Inclusions
,”
Acta Metall.
0001-6160,
21
, pp.
571
574
.
14.
Mura
,
T.
, 1987,
Micromechanics of Defects in Solids
,
2nd ed.
,
Martinus Nijhoff
,
Dordrecht
, pp.
168
170
.
15.
Taya
,
M.
, and
Chou
,
T. W.
, 1981, “
On Two Kinds of Ellipsoidal Inhomogeneities in an Infinite Elastic Body: An Application to a Hybrid Composite
,”
Int. J. Solids Struct.
0020-7683,
136
, pp.
553
563
.
16.
Taya
,
M.
, and
Mura
,
T.
, 1981, “
On Stiffness and Strength of an Aligned Short-Fiber Reinforced Composite Containing Fiber-End Cracks Under Uniaxial Applied Stress
,”
ASME J. Appl. Mech.
0021-8936,
48
, pp.
361
367
.
17.
Arsenault
,
R. J.
, and
Taya
,
M.
, 1987, “
Thermal Residual Stress in Metal Matrix Composite
,”
Acta Metall.
0001-6160,
35
, pp.
651
659
.
You do not currently have access to this content.