Morphology and shape memory effect of segmented polyurethanes. Part І: With crystalline reversible phase

Polymer ◽  
2007 ◽  
Vol 48 (17) ◽  
pp. 5133-5145 ◽  
Author(s):  
Feng Long Ji ◽  
Jin Lian Hu ◽  
Ting Cheng Li ◽  
Yuen Wah Wong
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Segmented Polyurethanes ◽  
Reversible Phase

Morphology, reversible phase crystallization, and thermal sensitive shape memory effect of cellulose whisker/SMPU nano-composites

2011 ◽  
Vol 123 (2) ◽  
pp. 749-762 ◽  
Author(s):  
Jianping Han ◽  
Yong Zhu ◽  
Jinlian Hu ◽  
Hongsheng Luo ◽  
Lap-Yan Yeung ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Nano Composites ◽  
Cellulose Whisker ◽  
Reversible Phase

SHAPE MEMORY INVESTIGATION OF SMART CAMAR LOGO USING NITI ALLOY WIRE

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Muhammad Safwan Shuhaimi ◽  
Nubailah Abd. Hamid ◽  
Rosliza Razali ◽  
Muhammad Hussain Ismail
Keyword(s):  
Phase Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Niti Alloy ◽  
Niti Shape Memory Alloy ◽  
Shape Effect ◽  
Niti Wire ◽  
The Wire ◽  
Reversible Phase

This project is investigates of NiTi shape memory alloy for simple smart application. The shape memory effect (SME) is attributed from the reversible phase transformation when subjected to stress and temperature. In this study, a small model of CAMAR logo was designed to mimic the shape memory effect. Three samples of wire were investigated; (i) Austenitic NiTi (ii) Martensitic NiTi and (iii) commercial plain carbon steel. The reversible austenite to martensite transformation of the NiTi wire was investigated by a differential scanning calorimetry (DSC) at temperatures ranging from -50 and 200oC. The wire was shaped into CAMAR logo using a mould and then heated at 500°C for 30 minutes in a high temperature furnace. To observe the shape effect recovery, the wire was straighten and reheated in warm water at different temperatures. Results showed that the austenitic wire exhibited complete shape memory recovery after heated at temperature approximately 35°C and  80°C. For the martensitic wire, complete recovery was only observed when the water temperature was ~ 80°C and no recovery was observed at ~30°C. This recovery effect was significantly influenced by the reversible phase transformation temperatures (PTTs) which attributed from the Austenite finish (Af) temperature.

Electric Field Induced Reversible Phase Transition in Li Doped Phosphorene: Shape Memory Effect and Superelasticity

2016 ◽  
Vol 138 (14) ◽  
pp. 4772-4778 ◽  
Author(s):  
Junkai Deng ◽  
Zhenyue Chang ◽  
Tong Zhao ◽  
Xiangdong Ding ◽  
Jun Sun ◽  
...  
Keyword(s):  
Phase Transition ◽  
Electric Field ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Reversible Phase Transition ◽  
Reversible Phase

Studies on thermally stimulated shape memory effect of segmented polyurethanes

1997 ◽  
Vol 64 (8) ◽  
pp. 1511-1516 ◽  
Author(s):  
Fengkui Li ◽  
Xian Zhang ◽  
Jianan Hou ◽  
Mao Xu ◽  
Xiaolie Luo ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Segmented Polyurethanes

A Viscoelastic-Plastic Constitutive Model of Shape Memory Polymer

2019 ◽  
Vol 35 (5) ◽  
pp. 601-611 ◽  
Author(s):  
Xueyao Zheng ◽  
Bo Zhou ◽  
Shifeng Xue
Keyword(s):  
Constitutive Model ◽  
Stationary Phase ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Memory Polymer ◽  
Memory Process ◽  
Mechanical Behaviors ◽  
Reversible Phase ◽  
Flow Element

ABSTRACTIt is of practical significance to develop a constitutive model which is able to predict the thermomechanical behaviors of the shape memory effect occurring in a shape memory polymer (SMP) accurately. The mechanism of shape memory effect of SMP is explained based on the assumption that SMP is composed by two phases, reversible phase and stationary phase. Especially the different flow elements are respectively added to the reversible phase and stationary phase in order to express the plastic behavior of SMP. There are two springs in series, one dashpot and one flow element in the reversible phase. There are two springs in parallel, one dashpot and one flow element in the stationary phase. A constitutive equation is developed to express the thermo-mechanical behaviors of shape memory effect in the SMP based on viscous-elastic mechanics and plastic theory. An internal variable, frozen ratio, is defined to follow the shape memory process in SMP, and the material properties are described as the functions of frozen ratio based on phase transition theorem. The developed constitutive model, which includes above constitutive equation and material parameter functions, is used to numerically simulate the thermo-mechanical behaviors of SMP under various load cycles. Results show that the developed constitutive model can not only predict the shape memory process of SMP accurately, but also express the rate-dependent behaviors of SMP effectively.

Shape memory effect and reversible phase crystallization process in SMPU ionomer

2007 ◽  
Vol 19 (4) ◽  
pp. 328-333 ◽  
Author(s):  
Yong Zhu ◽  
Jinlian Hu ◽  
Ka-fai Choi ◽  
Qinghao Meng ◽  
Shaojun Chen ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Crystallization Process ◽  
Reversible Phase

Tensile Failure of 55-Nitinol Wire

1975 ◽  
Vol 33 ◽  
pp. 46-47
Author(s):  
F. I. Grace
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Stoichiometric Composition ◽  
Tensile Failure ◽  
Initial State ◽  
Initial Shape ◽  
Nitinol Wire ◽  
Cscl Type ◽  
Shear Transformation

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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