scholarly journals Mechanical Properties and Contractile Force Mechanism of Shape Memory Alloy Knitted Fabric Actuator

2019 ◽  
Vol 65 (3) ◽  
pp. 47-53
Author(s):  
Akichika NAKASHIMA ◽  
Yusuke HIGUCHI ◽  
Yohei SATO ◽  
Lina WAKAKO ◽  
Toshiyasu KINARI
2021 ◽  
Vol 67 (1) ◽  
pp. 13-19
Author(s):  
Akichika NAKASHIMA ◽  
Yusuke HIGUCHI ◽  
Yohei SATO ◽  
Lina WAKAKO ◽  
Toshiyasu KINARI

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 80
Author(s):  
Bo Zhang ◽  
Sizhi Zeng ◽  
Fenghua Tang ◽  
Shujun Hu ◽  
Qiang Zhou ◽  
...  

As a stimulus-sensitive material, the difference in composition, fabrication process, and influencing factors will have a great effect on the mechanical properties of a superelastic Ni-Ti shape memory alloy (SMA) wire, so the seismic performance of the self-centering steel brace with SMA wires may not be accurately obtained. In this paper, the cyclic tensile tests of a kind of SMA wire with a 1 mm diameter and special element composition were tested under multi-working conditions, which were pretreated by first tensioning to the 0.06 strain amplitude for 40 cycles, so the mechanical properties of the pretreated SMA wires can be simulated in detail. The accuracy of the numerical results with the improved model of Graesser’s theory was verified by a comparison to the experimental results. The experimental results show that the number of cycles has no significant effect on the mechanical properties of SMA wires after a certain number of cyclic tensile training. With the loading rate increasing, the pinch effect of the hysteresis curves will be enlarged, while the effective elastic modulus and slope of the transformation stresses in the process of loading and unloading are also increased, and the maximum energy dissipation capacity of the SMA wires appears at a loading rate of 0.675 mm/s. Moreover, with the initial strain increasing, the slope of the transformation stresses in the process of loading is increased, while the effective elastic modulus and slope of the transformation stresses in the process of unloading are decreased, and the maximum energy dissipation capacity appears at the initial strain of 0.0075. In addition, a good agreement between the test and numerical results is obtained by comparing with the hysteresis curves and energy dissipation values, so the numerical model is useful to predict the stress–strain relations at different stages. The test and numerical results will also provide a basis for the design of corresponding self-centering steel dampers.


1994 ◽  
Author(s):  
Kuang-Hsi Wu ◽  
Y. Q. Liu ◽  
Michael J. Maich ◽  
Hsien-Kuei Tseng

2015 ◽  
Vol 1115 ◽  
pp. 454-457 ◽  
Author(s):  
Alala M. Ba Hamid ◽  
Mohatashem R. Makhdoomi ◽  
Tanveer Saleh ◽  
Moinul Bhuiyan

In Malaysia, every year approximately 40000 people suffer from stroke and many of them become immobilized as an after effect. Rehabilitation robotics to assist disabled people has drawn significant attention by the researchers recently. This project also aims to contribute to this field. This paper presents a Shape Memory Alloy (SMA) actuated wearable assistive robotic hand for grasping. The proposed design is compact and sufficiently light to be used as an assistive hand. It is a joint less structure, has the potential because the human skeleton and joint replace the robot’s conventional structure. This design has been implemented on index and thumb fingers to enable grasping. Shape memory alloy springs and bias force mechanism are used for purpose of hand’s flexion and extension. This paper describes the mechatronic design of the wearable hand, experimental study of actuation unit and sensory system. Open loop experiments are conducted to understand the hand characterization and grip force provided by index finger. Current, temperature, extension and contraction of shape memory alloy springs are reported. This mechanism requires approximately 2A current for the SMA to actuate which provides maximum of 1.6N of gripping force. Conducted experiments show promising results that encourage further developments.


2015 ◽  
Vol 18 (suppl 2) ◽  
pp. 35-38 ◽  
Author(s):  
Piter Gargarella ◽  
Cláudio Shyinti Kiminami ◽  
Eric Marchezini Mazzer ◽  
Régis Daniel Cava ◽  
Leonardo Albuquerque Basilio ◽  
...  

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