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Materials Congress 2018
Page 50
Nano Research & Applications
ISSN: 2471-9838
W o r l d C o n g r e s s o n
Materials Science & Engineering
A u g u s t 2 3 - 2 5 , 2 0 1 8
Am s t e r d a m , N e t h e r l a n d s
This study investigated the effects of geometric parameters, diameter and
crimped length, of superelastic shape memory alloy (SMA) fibers on their
pullout displacement recovering capacity. For this purpose, three diameters
of 0.5, 0.7 and 1.0 mm and two different crimped lengths of 5.0 and 10.0 mm
were considered for short fibers to be fabricated, with a length of 30 mm,
employing NiTi SMA Wires. The superelastic SMA wires had similar stress-
strain behaviour and temperature characteristics of phase transformation.
As previous studies indicated that the spear-head end provided greatest
anchoring action compared with other types of end shapes, to provide
anchoring action during the pullout test, fibers were crimped at the end part
and spear-head end was created. To conduct pullout tests, mortar specimens
with compressive strength of 84 MPa were prepared with a square shape at the
top and dog-bone shape at the bottom to be fixed in the grip. The embedded
length of each fiber in the mortar specimen was 15 mm. The pullout test
was performed with displacement control to obtain monotonic or hysteretic
behaviours. The results showed that pullout displacements were recovered
after fibers slipped. The superelastic SMA fibers with larger diameters showed
better pullout displacement recovering capacity. All fibers showed the flag-
shaped behaviour, and the fibers of 1.0 mm showed the clearest flag-shaped
behaviour. It was also observed that the length of fiber cramping did not affect
the pullout resistance of the superelastic SMA fibers.
Biography
Eunsoo Choi is a Professor in Hongik University, Seoul, Korea.
He received his BS and MS from the Hanyang University in
Seoul, and his PhD from the Georgia Institute of Technology,
Atlanta, GA. His research fields include the Application of Shape
Memory Alloys for Civil Engineering Structures and Seismic
Retrofits for Reinforced Concrete Structures.
Self-centering capacity of superelastic shape memory alloy
fibers in mortar
Eunsoo Choi1 , Hanchul Park1 , Doohyun Kim1 , Sang-yong Lee1
and Eunsol Kwon1
Seung-Wook Chae1 and Baksoon Cho2
1Hongik University, Korea
2INJE University, Korea
Eunsoo Choi et al., Nano Res Appl 2018, Volume: 4
DOI: 10.21767/2471-9838-C4-018