scholarly journals Effects of a Short Heat Treatment Period on the Pullout Resistance of Shape Memory Alloy Fibers in Mortar

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2278 ◽  
Author(s):  
Min Kyoung Kim ◽  
Dong Joo Kim ◽  
Young-Soo Chung ◽  
Eunsoo Choi
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Memory Effects ◽  
Stress Recovery ◽  
Pullout Resistance ◽  
Pullout Tests ◽  
Dog Bone ◽  
Shape Memory Effects ◽  
Short Time

The feasibility of the crack closure of cementitious composites reinforced with shape memory alloy (SMA) fibers was investigated by performing single-fiber pullout tests. To demonstrate the fast crack closing ability, in this study, a heat treatment (300 °C) was applied for a short time (10 min). A short heat treatment was applied for 10 min, after the slip reached 0.5 mm, to activate the shape memory effects of cold-drawn SMA fibers. Two types of alloys were investigated, NiTi and NiTiNb, with two geometries, either smooth or dog-bone-shaped. During the heat treatment, the pullout stress of the SMA fibers initially decreased due to thermal extension, and then increased after heating for 1–3 min, resulting from the shape memory effects. However, their pullout stress recovery during and after the heat treatment was different for the different alloys and fiber geometries. The NiTi fibers generally produced a higher and faster recovery in terms of their pullout stress than the NiTiNb fibers, while the dog-bone-shaped fibers showed a faster pullout stress recovery than the smooth fibers.

Superelastic and Shape Memory Effects in Laminated Shape-Memory-Alloy Beams

AIAA Journal ◽  
2003 ◽  
Vol 41 (1) ◽  
pp. 100-109 ◽  
Author(s):  
S. Marfia ◽  
E. Sacco ◽  
J. N. Reddy
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Memory Effects ◽  
Shape Memory Effects

Effects of short time heat treatment on superelastic properties of a Ti–Nb–Al biomedical shape memory alloy

2006 ◽  
Vol 438-440 ◽  
pp. 870-874 ◽  
Author(s):  
H. Hosoda ◽  
Y. Kinoshita ◽  
Y. Fukui ◽  
T. Inamura ◽  
K. Wakashima ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Short Time

Influence of Electrical Pulse on Shape Memory Effects and Phase Transition of FeMnSiCrNi Shape Memory Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 562-565
Author(s):  
Xing Jiang Liu ◽  
Yan Gao ◽  
Jin Gang Qi
Keyword(s):  
Shape Memory Alloy ◽  
Liquid Metal ◽  
Shape Memory ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Electric Pulse ◽  
Memory Effects ◽  
Grain Structure ◽  
Shape Memory Effects ◽  
Columnar Grain

This paper studies the electric-pulse applied in the solidification process of the FeMnSiCrNi shape memory alloy, by applying different pulse frequency and polarity on the FeMnSiCrNi shape memory alloy to improve the shape memory effects. The results show : electric-pulse was conducive to FeMnSiCrNi alloys grain refinement, the alloy can improve the shape memory effect of Compression deformation, the absolute shape recovery rate is improved from 2% to 3.2% which is not treated by the electric-pulse ; when the liquid metal was connected with the anode of the pulse, it is easy to get the columnar grain structure and the column spacing is smaller; when the liquid metal was connected with the cathode of the pulse, the column spacing is larger; Columnar grain is conducive to FeMnSiCrNi alloy specimens compressed shape recovery, it has the smaller column spacing, yet the shape recovery rate is higher; equiaxed is favor in bending back, columnar crystals impede the bending response.

Stress-strain behavior of Cu-Al-Ni single-crystal shape memory alloy at high temperature: shape memory effects

2004 ◽  
Author(s):  
Ganesh K. Kannarpady ◽  
Steve Trigwell ◽  
Abhijit Bhattacharyya ◽  
Ivan Viahhi ◽  
Sergei Pulnev
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Single Crystal ◽  
Shape Memory ◽  
Memory Effects ◽  
Crystal Shape ◽  
Stress Strain ◽  
Strain Behavior ◽  
Shape Memory Effects

scholarly journals Straining Behavior of Mortar Reinforced by Cold Drawn Crimped and Dog-Bone-Shaped Fibers under Monotonic and Cyclic Compressions

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1522
Author(s):  
Ha Vinh Ho ◽  
Eunsoo Choi ◽  
Duhyeon Kim ◽  
Joowon Kang
Keyword(s):  
Elastic Modulus ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Experimental Test ◽  
Damage Evolution ◽  
Pullout Resistance ◽  
Dog Bone ◽  
Plastic Phase ◽  
Mortar Matrix ◽  
Compressive Tests

The straining behavior of the shape memory alloy (SMA) fibers-reinforced mortar was investigated in this study by the monotonic compressive and cyclic compressive tests. Two types of SMA fibers with a crimped and dog-bone shape were used due to the high pullout resistance capacity, which guaranteed that the fibers and mortar matrix were composited well. The plain mortar was mixed with two different compositions to create the higher elastic modulus mortar matrix and the lower elastic modulus mortar matrix compared with the elastic modulus of SMA fibers. The results of the experimental test indicated that the non-heated SMA fibers could control the strains in both elastic and plastic phases; in which, the crimped fiber was more effective in precracking due to the higher composite capacity while the dog-bone-shaped fiber had a higher effect in post-cracking. After heating, the dog-bone-shaped fiber slipped more than that of the crimped fiber; thus, the heated crimped fiber was more effective than the heated dog-bone-shaped fiber in controlling strains after cracking. The effect of SMA fibers on the elastic modulus depended on both the elastic modulus of mortar matrix and the property of SMA fibers. In the plastic phase, the fibers were effective on reducing the speed of damage in monotonic case. An equation using reinforcing index was suggested for damage evolution in the cyclic case.

scholarly journals Harnessing reversible dry adhesion using shape memory polymer microparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19616-19622
Author(s):  
Wenbing Li ◽  
Junhao Liu ◽  
Wanting Wei ◽  
Kun Qian
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Memory Effects ◽  
Reversible Adhesion ◽  
Dry Adhesion ◽  
Bonding Property ◽  
Shape Memory Effects ◽  
Polymer Microparticles

Shape memory polymers can provide excellent bonding property because of their shape memory effects. This paper proposes an adhesive unit that is capable of repeatable smart adhesion and exhibits reversible adhesion under heating.

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