scholarly journals Characterization and Lubrication of Tube-Guided Shape-Memory Alloy Actuators for Smart Textiles

Robotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 94
Author(s):  
Tim Helps ◽  
Adithya Vivek ◽  
Jonathan Rossiter

Smart textiles are flexible materials with interactive capabilities such as sensing, actuation, and computing, and in recent years have garnered considerable interest. Shape-memory alloy (SMA) wire is a well-suited for smart textiles due to its high strength, small size, and low mass. However, the contraction of SMA wire is low, limiting its usefulness. One solution to increasing net contraction is to use a long SMA wire and guide it inside a tube that is wound back and forth or coiled inside a smart textile. In this article, we characterize the performance of tube-guided SMA wire actuators. We investigate the effect of turn radius and number of loops, showing that the stroke of an SMA-based system can be improved by up to 69.81% using the tube-guided SMA wire actuator concept. Finally, we investigate how tube-guided SMA wire actuators can be lubricated to improve their performance. Coarse graphite powder and tungsten disulfide lubricant both delivered improvements in stroke compared with an unlubricated system.

2020 ◽  
Vol 28 ◽  
pp. 2110-2117
Author(s):  
Fedor S. Belyaev ◽  
Margarita E. Evard ◽  
Eugeny S. Ostropiko ◽  
Aleksandr E. Volkov

2018 ◽  
Vol 30 (2) ◽  
pp. 283-307 ◽  
Author(s):  
Md Arman Chowdhury ◽  
Ahmad Rahmzadeh ◽  
Saber Moradi ◽  
M Shahria Alam

Driven by a need to reduce repair costs and downtime in structures following a major earthquake, self-centering systems have been introduced. Post-tensioned high strength steel strands have shown promising results in providing self-centering capability in steel frames, where the beams are compressed to columns. This study aims at investigating the feasibility of using reduced length of steel and shape memory alloy strands in steel beam–column connections. Through finite element modeling, the study first evaluates the effect of using short-length regular post-tensioned strands in steel connections. The results show higher strength, stiffness, and energy dissipation capacity for connections with shorter length regular post-tensioned strands. The moment capacity and energy absorption capacity of a post-tensioned beam–column connection with one-third strand length were 105% and 114% higher than those of with full-length strands, respectively. However, residual drifts increased from 4 to 39 mm. To avoid loss in the re-centering capability of such connections due to yielding/failing of post-tensioned steel strands, the application of shape memory alloy and hybrid strands are proposed. The results show that shorter length shape memory alloy strands are effective in regaining self-centering and dissipating higher amount of energy compared to the full-length steel strands.


2013 ◽  
Vol 102 (23) ◽  
pp. 231905 ◽  
Author(s):  
Shijie Hao ◽  
Lishan Cui ◽  
Daqiang Jiang ◽  
Cun Yu ◽  
Jiang Jiang ◽  
...  

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Xudong Zhang ◽  
Hongxiang Zong ◽  
Lishan Cui ◽  
Xueling Fan ◽  
Xiangdong Ding ◽  
...  

2018 ◽  
Vol 763 ◽  
pp. 661-668
Author(s):  
Cheng Fang ◽  
Wei Wang ◽  
Xiao Yang

This paper presents a feasibility study on a self-centering steel column foot equipped with innovative shape memory alloy (SMA) ring springs. The ring spring system includes a series of SMA outer rings and high-strength alloy inner rings stacked in alternation with mating taper faces, and the system is used in conjunction with high-strength bolts in a typical extended end-plate connection to achieve favorable self-centering and energy dissipation performances while ensuring ease of construction. An experimental investigation was first conducted looking into the basic mechanical performance of individual SMA ring springs under cyclic loading. Driven by the superelastic behavior of SMA, excellent self-centering ability with satisfactory energy dissipation is exhibited. Subsequently, a further experimental study on a proof-of-concept column foot specimen is conducted, where the key properties, including ductility, self-centering ability, and energy dissipation capability, are discussed in detail in this paper.


2019 ◽  
Vol 787 ◽  
pp. 963-971 ◽  
Author(s):  
Anna Eftifeeva ◽  
Elena Panchenko ◽  
Yuriy Chumlyakov ◽  
Eleonora Yanushonite ◽  
Gregory Gerstein ◽  
...  

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