Effect of glucose crosslinking on thermomechanical properties and shape memory effect of PET‐PEG copolymers

2008 ◽  
Vol 109 (6) ◽  
pp. 3533-3539 ◽  
Author(s):  
Yong‐Chan Chung ◽  
Yong Shik Shim ◽  
Byoung Chul Chun
2007 ◽  
Vol 34 (9) ◽  
pp. 1075-1086 ◽  
Author(s):  
M S Alam ◽  
M A Youssef ◽  
M Nehdi

Shape memory alloys (SMAs) are special materials with a substantial potential for various civil engineering applications. The novelty of such materials lies in their ability to undergo large deformations and return to their undeformed shape through stress removal (superelasticity) or heating (shape-memory effect). In particular, SMAs have distinct thermomechanical properties, including superelasticity, shape-memory effect, and hysteretic damping. These properties could be effectively utilized to substantially enhance the safety of various structures. Although the high cost of SMAs is still limiting their use, research investigating their production and processing is expected to make it more cost-competitive. Thus, it is expected that SMAs will emerge as an essential material in the construction industry. This paper examines the fundamental characteristics of SMAs, the constitutive material models of SMAs, and the factors influencing the engineering properties of SMAs. Some of the potential applications of SMAs are discussed, including the reinforcement and repair of structural elements, prestress applications, and the development of kernel components for seismic devices such as dampers and isolators. The paper synthesizes existing information on the properties of SMAs, presents it in concise and useful tables, and explains different alternatives for the application of SMAs, which should motivate researchers and practicing engineers to extend the use of SMAs in novel and emerging applications.Key words: shape memory alloy, superelasticity, shape-memory effect, construction, retrofitting.


2012 ◽  
Vol 190 ◽  
pp. 295-298 ◽  
Author(s):  
K. Akatyeva ◽  
V. Afonina ◽  
F. Albertini ◽  
S. von Gratowski ◽  
A. Irzhak ◽  
...  

The melt spun ribbons of ferromagnetic shape-memory alloy (FSMA) Ni53Mn24Ga23 have been prepared by rapid quenching. Thermomechanical properties have been studied by multi-point technique and perfect shape memory effect (SME) observed. The magnetic field effect on thermomechanical behavior was studied by placing multi-point press into Bitter magnet. A giant (1.2%) bending strain, due to magnetic field-induced martensitic transformation (magnetic-field-induced SME), has been observed at a constant temperature T= 56 °C in a field of 6 T. At least 80% of martensitic transformation reversibly induced by the external field was observed experimentally. Submicron sized samples of the alloy with thicknesses down to 300 nm have been milled by focused ion beam (FIB) technique. The deformation behavior of these samples was studied by Omniprobe micromanipulator in the vacuum chamber of FIB device. The SME response was tested in situ by heating the samples with a semiconductor laser. Strong two-way SME was observed due to bending strains of the samples under study.


2001 ◽  
Vol 34 (18) ◽  
pp. 6431-6437 ◽  
Author(s):  
Bo Sun Lee ◽  
Byoung Chul Chun ◽  
Yong-Chan Chung ◽  
Kyung Il Sul ◽  
Jae Whan Cho

2017 ◽  
Vol 696 ◽  
pp. 310-314 ◽  
Author(s):  
E. Barmina ◽  
A. Kosogor ◽  
V. Khovaylo ◽  
M. Gorshenkov ◽  
M. Lyange ◽  
...  

2021 ◽  
pp. 40-43
Author(s):  

The features of the friction process during burnishing of couplings made of the shape memory alloy are considered. The influence of temperatures on the thermomechanical properties of the alloy of the part during burnishing was investigated. The selection of lubricant for burnishing of parts at cryogenic temperatures is analyzed. Keywords: burnishing, nitinol, shape memory effect. [email protected], [email protected]


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.


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