Актуатор с последовательным соединением стержня из сплава с памятью формы и упругого элемента смещения

Author(s):  
А. А. Мовчан ◽  
◽  
Н. М. Экстер ◽  

One of the most promising applications of shape memory alloys (SMA) is their use for creating working bodies of power exciters (actuators). The working body of the actuator must perform certain movements due to shape memory phenomena (heating, working stroke of the actuator) and the accumulation of direct transformation deformations (cooling, idling of the actuator). It is known that the process of deformation of SMA during cooling occurs only in the presence of mechanical action, while the return to the original form during heating occurs in the absence of a corresponding mechanical action and even in the presence of a sufficiently large counteraction. To ensure the possibility of not only working, but also idling of the actuator, the working body of the SMA is connected to the elastic bias element so that both of these elements are deformed together. In this case, when the SMA element is heated, it is deformed due to the shape memory phenomenon, which leads to the deformation of the bias element associated with the working body and the appearance, both in this element and in the working body, of mechanical stresses that increase with the temperature of the SMA element. It is these stresses, which continue to act during the cooling of the working body, that ensure its deformation in the opposite direction at the stage of cooling of the working body and the corresponding direct transformation into SMA. In this paper, the behavior of an actuator consisting of a SMA rod and an elastic rod (an bias element) connected in series, the total length of which is assumed to be unchanged, is analytically investigated. The influence of the system parameters on the stresses in the SMA rod and the value of the working stroke of the actuator is investigated. The conditions for the implementation of the closed two way shape memory effect in this system are determined.

Author(s):  
Т.А. Шалыгина ◽  
С.Ю. Воронина ◽  
А.Ю. Власов ◽  
К.А. Пасечник ◽  
И.В. Обверткин

The possibility of using a three-point bending clamp thermomechanical analyzer for study the shape memory effect of a constructional polyurethane composite is investigated. The viscoelastic properties of the sample in the region of the transition from the glassy to the highly elastic state are studied. The parameters affecting the recovery rate of the original form (Rr) and the fixation factor of the temporary form (Rf) are determined. The conditions for deforming and cooling the polyurethane composite are established, which allow to achieve the values of Rr = 99.98% and Rf = 99.70%.


2016 ◽  
Vol 684 ◽  
pp. 523-529
Author(s):  
Vladimir Glushchenkov ◽  
Rinat Yu. Yusupov ◽  
Valentina Alekhina ◽  
Yuri Egorov

The report provides designs of actuators from the shape memory material-nitinol. It is proposed to use rods, wire, sheets and tape as working elements of the actuators. Special attention is paid to the designs of composite multil-element actuators, working elements of which are connected in parallel or in series. The experimental technique and results of experiments on evaluation of stresses developed by such actuators are given. It is shown that using the composite actuators from thin working elements facilitates control over their heating and cooling.


Author(s):  
F. I. Grace

An interest in NiTi alloys with near stoichiometric composition (55 NiTi) has intensified since they were found to exhibit a unique mechanical shape memory effect at the Naval Ordnance Laboratory some twelve years ago (thus refered to as NITINOL alloys). Since then, the microstructural mechanisms associated with the shape memory effect have been investigated and several interesting engineering applications have appeared.The shape memory effect implies that the alloy deformed from an initial shape will spontaneously return to that initial state upon heating. This behavior is reported to be related to a diffusionless shear transformation which takes place between similar but slightly different CsCl type structures.


2003 ◽  
Vol 112 ◽  
pp. 1177-1180 ◽  
Author(s):  
A. Schuster ◽  
H. F. Voggenreiter ◽  
D. C. Dunand ◽  
G. Eggeler

2003 ◽  
Vol 112 ◽  
pp. 765-768 ◽  
Author(s):  
Y. Bellouard ◽  
R. Clavel ◽  
R. Gotthardt ◽  
J. van Humbeeck

Author(s):  
M Bolat ◽  
A Ciocan-Pendefunda ◽  
Z Surlari ◽  
C Bida ◽  
C Balcos ◽  
...  

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