A Three-Point Bending Test Machine for Studying the Thermomechanical Properties of Shape Memory Alloys

2018 ◽  
Vol 61 (2) ◽  
pp. 306-312 ◽  
Author(s):  
V. S. Kalashnikov ◽  
V. V. Koledov ◽  
D. S. Kuchin ◽  
A. V. Petrov ◽  
V. G. Shavrov
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Thermomechanical Properties ◽  
Bending Test ◽  
Test Machine ◽  
Three Point Bending

Cold Bending a Ni-Ti Shape Memory Alloy Wire

2015 ◽  
Vol 661 ◽  
pp. 98-104 ◽  
Author(s):  
Kuang-Jau Fann ◽  
Pao Min Huang
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Room Temperature ◽  
Aging Treatment ◽  
Treatment Temperature ◽  
Bending Test ◽  
Solution Treatment Temperature

Because of being in possession of shape memory effect and superelasticity, Ni-Ti shape memory alloys have earned more intense gaze on the next generation applications. Conventionally, Ni-Ti shape memory alloys are manufactured by hot forming and constraint aging, which need a capital-intensive investment. To have a cost benefit getting rid of plenty of die sets, this study is aimed to form Ni-Ti shape memory alloys at room temperature and to age them at elevated temperature without any die sets. In this study, starting with solution treatments at various temperatures, which served as annealing process, Ni-rich Ni-Ti shape memory alloy wires were bent by V-shaped punches in different curvatures at room temperature. Subsequently, the wires were aged at different temperatures to have shape memory effect. As a result, springback was found after withdrawing the bending punch and further after the aging treatment as well. A higher solution treatment temperature or a smaller bending radius leads to a smaller springback, while a higher aging treatment temperature made a larger springback. This springback may be compensated by bending the wires in further larger curvatures to keep the shape accuracy as designed. To explore the shape memory effect, a reverse bending test was performed. It shows that all bent wires after aging had a shape recovery rate above 96.3% on average.

An Estimation of Joint Strength by Using Fe-Based Shape Memory Alloy Subjected to Bending Deformation at Various Deformation Rate

2014 ◽  
Vol 626 ◽  
pp. 228-233 ◽  
Author(s):  
Kazuki Fujita ◽  
Keizo Nishikori ◽  
Takeshi Iwamoto
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Deformation Rate ◽  
Bending Strength ◽  
Rate Sensitivity ◽  
Force Balance ◽  
Bending Test ◽  
Structural Members ◽  
Bending Deformation ◽  
Three Point Bending

In various kinds of shape memory alloy (SMA), Fe-based SMA (Fe-SMA) shows smaller shape memory effect compared with the other SMAs. However, Fe-SMA shows huge advantages on the excellent formability, machinability, etc. Moreover, its production cost is cheaper than other SMAs; therefore, the alloy is attempted to be applied to structural members such as joints and dampers. Since bending deformation at higher deformation rate is generated in the members, especially the joints, due to impact force such as earthquake or wind, a clarification on the bending strength of the joints at various deformation rate is strongly required. In this study, at first, it is attempted that the bending strength and its rate sensitivity of the joints which consist of Fe-based SMA are experimentally estimated by the three-point bending test at various deformation rate. Then, the force balance equation is challenged to be derived to predict the bending strength.

Utilizing shape memory alloys to enhance the performance and safety of civil infrastructure: a review

2007 ◽  
Vol 34 (9) ◽  
pp. 1075-1086 ◽  
Author(s):  
M S Alam ◽  
M A Youssef ◽  
M Nehdi
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Thermomechanical Properties ◽  
Engineering Properties ◽  
Civil Infrastructure ◽  
Structural Elements ◽  
Potential Applications ◽  
Constitutive Material

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.

Effect of Ta Addition on Properties and Microstructures of Fe-28Ni-11.5Al Shape Memory Alloys

2014 ◽  
Vol 787 ◽  
pp. 288-294 ◽  
Author(s):  
Wen Yi Peng ◽  
Neng Wu Yang ◽  
Gui Li Qu ◽  
Wei Wei Wang ◽  
Hai Ping Shi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Thermal Expansion ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Test Machine ◽  
X Ray Diffraction ◽  
Recoverable Strain ◽  
The Mean

The effects of Ta additions (x=0, 0.5, 1.0, 1.5) in Fe60.5-xNi28Al11.5Tax(at.%) shape memory alloys on microstructure, thermal expansion, and pseudoelasticity of the aged alloys were investigated by metallurgical microscope, X-ray diffraction, SEM, EDS, high-temperature dilatometer spectrometer and pressure test machine. The results showed that with the increment of Ta additions, the γ' phase content increased which strengthened the austenitic matrix, meanwhile the compressive strength, the recoverable strain and the maximum strain of the aging state alloys decreased first and then increased, and the alloy’s residual strain firstly decreased and then increased. When the Ta content was 1.0 at.%, the alloy’s compressive strength, recoverable strain and plastic deformation strain reached its maximum value, 2.5Gpa, 14.4%, and 16.0% respectively. Thus, the alloy had the best pseudo-elastic at this time. The mean thermal expansion coefficient of the alloys decreased with Ta additions, when the Ta content was 1.0 at.%, the mean thermal expansion coefficient was at its minimum.

The Use of Correlation and Frequency Analysis for Detection of Deformation in 7050 Aluminum Beams

2015 ◽  
Vol 655 ◽  
pp. 263-266
Author(s):  
Fei Yi Liao ◽  
Shi Jun Li ◽  
Yuan Lin
Keyword(s):  
Frequency Domain ◽  
Lead Zirconate Titanate ◽  
Lamb Waves ◽  
Piezoelectric Materials ◽  
Lead Zirconate ◽  
Bending Test ◽  
Test Machine ◽  
Three Point Bending ◽  
Potential Applications ◽  
Aluminum Beam

Lead zirconate titanate (PZT) is one of the most widely used ferroelectric and piezoelectric materials. Its piezoelectricity is widely used in the applications of structural health monitoring (SHM). Here, we use PZT ceramics as sensors to detect the deformation of structure using guided Lamb waves. In order to well analyze the multi-modes of Lamb waves and achieve detection of deformation in superposed wave peaks, correlation and Fourier transform were used to extract peaks in both time and frequency domain. In this paper, a 7050 aluminum beam and three-point bending test machine were utilized to test the changes of waves when different deformations were introduced. With the adjustment of correlation index, change of time delay and new peaks occurring in time domain demonstrated the change of deformations. In frequency domain, the change of central frequencies and magnitudes also demonstrated the change of deformations. The study shows the potential applications of PZT sensors in detection of deformation.

Thermomechanical properties in CuAlNi shape memory alloys processed by powder metallurgy

1996 ◽  
Author(s):  
J. San Juan ◽  
R. B. Perez-Saez ◽  
V. Recarte ◽  
I. Saez-Ocariz ◽  
M. L. No ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Thermomechanical Properties

Development of Fe-Mn-Si-Cr Shape Memory Alloy Fiber Reinforced Plaster-Based Smart Composites

2005 ◽  
Vol 475-479 ◽  
pp. 2063-2066 ◽  
Author(s):  
Teppei Wakatsuki ◽  
Yoshimi Watanabe ◽  
Hiroshi Okada
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Tensile Strain ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Three Point Bending ◽  
Smart Composites ◽  
Fiber Holder

In previous studies, it has been found that the shape memory effect of the embedded straight and wavy shape memory alloy (SMA) fibers enhance the strength and energy absorption prior to fracture of the composite, where the embedded SMA fibers shrink due to their shape memory effect. In the case of wavy fiber reinforced composites, the SMA fibers were subjected to pre-tensile strain using fiber holder with rotatable rollers to maintain the constant periodicity and amplitude of wavy fibers. In this study, on the other hand, the wavy SMA fibers were subjected to pre-tensile strain without using fiber holder, and therefore, periodicity and amplitude of wavy fibers were varied during the deformation. Then the wavy SMA fiber reinforced smart composite is fabricated. For the mechanical property characterization, three-point bending test is performed for the specimens.

Effect of Deflection Rate on Bending Deformation Behavior of Fe-Based Shape Memory Alloy

2014 ◽  
Vol 566 ◽  
pp. 116-121
Author(s):  
Keizo Nishikori ◽  
Takeshi Iwamoto
Keyword(s):  
Shape Memory ◽  
Static Loading ◽  
Deformation Behavior ◽  
Rate Sensitivity ◽  
Bending Test ◽  
Bending Deformation ◽  
Three Point Bending ◽  
Positive Rate ◽  
The Impact ◽  
Deflection Rate

In this study, three-point bending test is conducted at various deformation rate by using a thin plate of Fe-based alloy. The rate sensitivity of its bending deformation during loading and shape memory effect by heating after unloading are investigated experimentally. The results obtained are summarized as bellows. (1) In the case where the quasi-static loading was applied, the positive rate sensitivity, which means the stress level increases with increasing the deflection rate, can be observed slightly. (2) It is hard to observe that recovery of deflection by SME depends on deflection rate under quasi-static loading. (3) In the case where the impact loading was applied, the positive rate sensitivity can be observed clearly.

Shape Recovery Characteristics of Pipes With Heavy Wall Thickness Made by Ferrous Shape Memory Alloy

2004 ◽  
Author(s):  
Yoshinori Joto ◽  
Manabu Wada ◽  
Hisashi Naoi ◽  
Tadakatsu Maruyama
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Wall Thickness ◽  
Shape Recovery ◽  
Chemical Compositions ◽  
Test Machine ◽  
Core Tube ◽  
Recovery Strain ◽  
Ferrous Shape Memory Alloy

Recently, ferrous shape memory alloys have been developed. Shape recovery strains of ferrous shape memory alloys are smaller than those of Ti-Ni shape memory alloys[1,2]. Strength, ductility and workability of the former alloy are higher than those of the latter alloy. Therefore, ferrous shape memory alloys are tried to apply for several kinds of pipe joints, as an example, joints of support pipes in the tunnel[3]. One of the other applications, the alloys is used as the material of simulation model to analyze the deformation behavior of the core tube in the fast breeder reactor. In this study, we investigated the shape recovery characteristics of pipes with heavy wall thickness made by ferrous shape memory alloy. Chemical compositions of this alloy are Fe, 28%Mn, 6%Si and 5%Cr. The alloy is melted, and round bars are manufactured by rolling, and pipes are machined from them. Tensile strength is 1100MPa, and yield strength is 320MPa. Ratios of wall thickness to central diameter of pipes are 10, 15, 20 and 25%. We insert tapered punch in the pipe, and expanded it by test machine. Then the circumferential strain of the center diameter of the pipes is 7%. And finally, the heat treatment is conducted at 350 degrees C in order to induce the shape recovery strain, and the pipe diameter decreases by means of austenitic transformation. The results obtained by the experiment are shown as follows. As the value of ratios of wall thickness to center diameter decreases, shape recovery strain increases and seems to approach the shape recovery strain obtained by uni-axial tension test, which was conducted in the past time.

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