Superelastic and cyclic response of niti sma at various. Theory and experimental studies is devoted to the phenomenon of pseudoelasticity superelasticity exhibited by shape memory alloy materials. Tensile and superelastic fatigue characterization of niti shape memory cables muhammad m. Superelastic and superplastic alloys problem set 2. Pdf shapememory alloys possess a number of unique characteristics, such as shape memory and superelasticity. Applications and development of shapememory and superelastic alloys in japan. Analysis of spherical indentation of superelastic shape memory alloys wenyi yan a, qingping sun b, xiqiao feng c, linmao qian d a school of engineering and information technology, deakin university, geelong, victoria 3217, australia b department of mechanical engineering, the hong kong university of science and technology, hong kong, china c department of engineering mechanics, tsinghua. When mechanically loaded, a superelastic alloy deforms reversibly to very high strains up to 10% by the creation of a stressinduced phase. These materials are often made from metal alloys, which can generate large stresses with small shape changes.
If a stress is applied to a shape memory alloy in the temperature range between af and a. Constitutive modeling and numerical simulation of multivariant phase transformation in superelastic shapememory alloys youngjean jungy, panayiotis papadopoulosy and r. In this way, the materials do not actually generate energy, but rather store and release potential energy. In this paper, the seismic performance of rc frames retrofitted using external superelastic sma bars is investigated and compared to the behaviour of a regular steel rc frame structure.
Shape memory and superelastic alloys possess properties not present in ordinary metals meaning that they can be used for a variety of applications. The objective of this study was to develop a numerical model of the superelastic behavior of shape memory alloys sma on a macroscale level. Sep 20, 2018 one way to minimize these residual deformations is by using smart materials such as superelastic shape memory alloys smas. Selfhealing is an essential property of smart concrete structures. This yielding jeopardizes the serviceability of these buildings as it results in residual lateral deformations. Mechanical properties of ti24 mol% nbbased shape memory alloys sma containing 3 mol% ga or ge were characterized in this paper as a part of our systematic work for the development of. Superelastic applications shapememory alloys have unique properties which are not present in many materials traditionally used in engineering applications. Such a hysteresis has the benefit of some energy dissipation along with minimal residual deformations upon removal of the load, hence is mostly preferred for recentering devices. Reinforced concrete rc framed buildings dissipate the seismic energy through yielding of the reinforcing bars. Pseudoelasticity of shape memory alloys sciencedirect. Japanese material scientists develop new superelastic alloy. Shape memory niti alloys exploit the ability of the materials to recover a trained shape upon heating above their transformation temperatures. Seismic performance of reinforced concrete frames retrofitted.
This thesis explored a strategy for adding ductility. Applications and development of shapememory and superelastic. Shape memory alloys are a class of metallic alloys that can remember their original shape upon being deformed. Superelastic alloys belong to the larger family of shape memory alloys. The effects of aging on the shapememory properties of ni 45. Present and future applications of shape memory and.
Bondslip behavior of superelastic shape memory alloys for. Cyclic properties of superelastic shape memory alloy. The international organization on shape memory and superelastic technologies smst is a volunteer organization made up of industry professionals, scientists and researchers dedicated to disseminating technical education on the unique class of materials which exhibit shape memory and superelastic properties. Ritchiez ydepartment of mechanical engineering zdepartment of materials science and engineering university of california, berkeley, ca 947201740, usa.
Youssef department of civil and environmental engineering, the university of western ontario london, ontario, n6a 5b9, canada received march 25, 2008, accepted june 29, 2009 abstract. Applications and technologies explores these applications discussing their key features and commercial performance. The basis for the shape memory and superelastic properties of smas is a martensitic phase transformation in the microstructure. Seismic performance of concrete frame structures reinforced. The shapememory prope rties are caused by reversible martensitic. Readers will gain invaluable information and insight into the current and potential future applications of shape memory alloys. Shape memory alloys smas are materials that can be deformed at one temperature but when heated or cooled, return to their original shape, i. Pdf electricalmechanical monitoring of shape memory. Superelastic shape memory alloy composite bars for reinforcing concrete structures. Such a material will also exhibit good superelastic properties at body temperature 37c. Pdf electricalmechanical monitoring of shape memory alloy. Analysis of spherical indentation of superelastic shape. Experimental investigation and modeling of the loading rate. Mar 28, 2011 summary this chapter contains sections titled.
Sep 27, 20 shape memory materials convert heat into strain and vice versa. Metallurgy a lightweight shapememory magnesium alloy. Superelastic and thermally activated tini alloys and their applications in dentistry p. Multiresponse optimization of wedm process parameters. Home materials science forum shape memory materials and their applications applications and development of shapememory and. Shape memory alloy wire and bars are tested to evaluate the effect of bar size and loading history on the strength, equivalent damping, and recentering properties.
Superelastic and superplastic alloys projects mechanical. Accordingly, their use introduces new design capabilities, which make it possible to improve device performance as well. Polycrystalline femnalni shape memory alloys show a small temperature dependence of the superelastic stress because of a small. Here we present a mg sma showingsuperelasticityof 4. Present and future applications of shape memory and superelastic materials volume 360 t. Shape memory alloys smas are metallic alloys which can recuperate permanent strains when they are heated above a fix temperature. Cast replicated niticu foams with superelastic properties, metallurgical and materials transactions a, 438 29392944 august 2012. Superelastic alloys comprise the largest volume of nitinol material. Shape memory alloys smas can be used as thermal actuators by using the property that when they are in an undeformed shape at a temperature higher than a f, they can be cooled to a temperature below m f to cause a reversible shape change. This shape recovery ability is due to reversible phase transformations between different solid phases of the material. While all niti shape memory alloys exhibit both superelasticity and the shape memory effect, this study is restricted to a temperature range over which only the super.
We propose a new analytical model for a superelastic shape memory alloy prismatic cantilever beam subjected to a concentrated force at the tip. Corrosion of shape memory and superelastic alloys uhlig. An actuation assembly adapted for driving a load and protecting against overloading and overheating conditions, includes an actuator defining a stroke when exposed to an activation signal, and further includes a protection device comprising a superelastic shape memory alloy element connected in series to and cooperatively configured with the actuator, and operable to both produce a secondary. Polycrystalline femnalni shape memory alloys show a small temperature dependence of the superelastic stress because of a. Corrosion of shape memory and superelastic alloys uhligs. Superelastic applications shape memory alloys have unique properties which are not present in many materials traditionally used in engineering applications. When the load is removed, the new phase becomes unstable and the material regains its original shape. This thesis explored a strategy for adding ductility and energy dissipation to frp reinforcing bars through the use of smafiber. To this avail, a mathematical framework recently developed by raniecki and mroz is utilized to. Lawrence yao mechanical engineering department, columbia university new york, ny 10027 abstract this work focuses on application of the laser forming process to niti shape memory alloys. Mar 03, 2016 shape memory alloys smas seminar and ppt with pdf report. Superelastic shape memory alloy sma exhibits the ability to undergo large deformations before reverting back to its undeformed shape following the removal of the load.
The main key feature of all smas is the occurrence of a martensitic part transformation. One of the shape memory alloys which possesses superelasticity and biocompatibility is nickeltitanium alloy. Accordingly, their use introduces new design capabilities, which make it possible to improve device performance as well as to propose innovative solutions. Results from a study on this behavior under tension and pure bending tests are presented and discussed. Full text views reflects the number of pdf downloads, pdfs sent. Shahria alam 2015 studied the feasibility study of utilizing superelastic shape memory alloy sma plates in steel beam. Analysis of spherical indentation of superelastic shape memory alloys wenyi yan a, qingping sun b, xiqiao feng c, linmao qian d a school of engineering and information technology, deakin university, geelong, victoria 3217, australia.
Shape memory alloys smas seminar and ppt with pdf report. Constitutive modelling and numerical simulation of multivariant phase transformation in superelastic shapememory alloys youngjean jung1, panayiotis papadopoulos1. First, by consisting in determining the transformations of equiatomic tini shape memory alloys by differential scanning calorimeter. The force is gradually increased and then removed and. Characterisation and modelling of behaviour of a shape. Superelastic tension and bending characteristics of shape. Modeling of superelastic shape memory alloy elements. In this article, the zakimoumni zm model for shape memory alloys is extended to account for tensilecompressive asymmetry over a wide temperature range. Experimental investigation and modeling of the loading.
The international organization on shape memory and superelastic technologies smst is a volunteer organization made up of industry professionals, scientists and researchers dedicated to disseminating technical education on the unique class of materials which exhibit shape memory and. Then, in order to validate a 3d numerical model of the pseudoelastic behaviour of sma allowing a finite strain analysis, a set of experimental tests at various initial temperatures is proposed. A metallurgical phase diagram for a metallic alloy is a schematic represen tation of the equilibrium conditions between distinct phases. Microstructure and shape memory behavior of 111oriented nitihfpd alloys e acar, h tobe, h e karaca et al. The proposed connections with sma plates could return to their original positions, while exhibiting a. It is believed that the super wear resistance of shape memory alloys is mainly due. Constitutive modeling and numerical simulation of multivariant phase transformation in superelastic shape memory alloys youngjean jungy, panayiotis papadopoulosy and r. Ceramics have certain characteristics that underlie shape memory transformation, but generally crack under strain. Materials free fulltext uniaxial compressive behavior. Shape memory alloys smas seminar ppt and pdf report. The hysteresis loop of an sma element looks like a flag.
One way to minimize these residual deformations is by using smart materials such as superelastic shape memory alloys smas. Superelastic shape memory alloys smas are a class of metallic alloys that have the unique property of being able to undergo large amounts of plastic strain while remaining elastic and dissipating energy. It provides extensive introductory content on the stateoftheart in the field, including sma materials development, definition of shape memory effects, and. To characterize the thermomechanical response, especially the superelastic behavior of niti shapememory alloys smas at various temperatures and strain rates, we have performed a series of both quasistatic and dynamic uniaxial compression tests on cylindrical samples, using an instron servohydraulic testing machine and ucsds enhanced hopkin. Ritchiez ydepartment of mechanical engineering zdepartment of materials science and engineering university of california, berkeley, ca 947201740, usa table of contents 1. Shape memory and superelastic alloys sciencedirect. Shape memory alloys for microsystems materials technology. Part i introduced the fundamental, room temperature, tensile responses of two cable designs 7. This topic discusses the modeling of shape memory alloy sma elements in etabs, sap2000, and csibridge.
This unique property underlies its great potential in the seismic design and retrofitting of structure members. Us9316212b2 superelastic shape memory alloy overloading. Magnetic shape memory and shape memory alloys other than titanium based. Shape memory and superelasticity is pleased to announce that diffusive phenomena and the austenitemartensite relative stability in cubased shapememory alloys from volume 4, issue 1, march 2018, is the winner of the 2018 best paper award. Recent experimental research indicates that superelastic shape memory alloy nickeltitanium niti is superior to stainless steel against wear and could be applied in tribological engineering. When the load is removed, the new phase becomes unstable and the. Ritchie a, a department of materials science and engineering, university of california, berkeley, ca 947201760, usa b department of mechanical engineering, university of california, berkeley, ca 94720, usa. For example, compare the fracture strength in terms of fracture stress and plane strain fracture toughness of ni and ti for the niti alloy. In this paper, superelastic sma wires were utilized to confine concrete cylinders to enhance their axial.
Pdf modeling tensilecompressive asymmetry for superelastic. Analytical model for a superelastic timoshenko shape. This study investigates bond characteristics and load transfer mechanisms between nsm sma reinforcement and concrete. The effects of laser forming on niti superelastic shape. Superelastic and shape memory properties of tixnb3zr2ta. Pseudoelasticity of shape memory alloys 1st edition. Introduction nitinol is a nickeltitanium alloy which exhibits outstanding properties such as shape memory, superelasticity, and biocompatibility.
Apr 27, 2016 this topic discusses the modeling of shape memory alloy sma elements in etabs, sap2000, and csibridge. In contrast to other structural metals, shape memory alloys smas offer two unique effects. Materials free fulltext uniaxial compressive behavior of. The phase transformation can be mechanically induced superelastic effect or thermally induced shape memory. Dipartimento di ingegneria civile, via della ricerca scientifica, 003 rome. Analytical model for a superelastic timoshenko shape memory. Ritchie2 1department of mechanical engineering, university of california, berkeley, ca 947201740, u. The special behavior of sma materials, also called shape memory effects, is described.
The first chapter of this book delivers a general introduction about the field of shape memory alloys treated as a generic example of adaptive material. The effects of laser forming on niti superelastic shape memory alloys this work focuses on application of the laser forming process to niti shape memory alloys. Jul 01, 2011 japanese material scientists develop new superelastic alloy. Seismic performance of concrete frame structures reinforced with superelastic shape memory alloys m. This paper constitutes the second part of our experimental study of the thermomechanical behavior of superelastic niti shape memory alloy cables. Schematic stress strain curve of superelastic shape memory alloy, showing the phenomena. Shape memory and superelastic ceramics at small scales. A fuzzy model of superelastic shape memory alloys for vibration control in civil engineeringapplications o e ozbulut, c mir, m o moroni et al. Shape memory materials convert heat into strain and vice versa. This study explores the superelastic behavior of a recently developed ni 45.
Constitutive modelling and numerical simulation of. It is believed that the super wear resistance of shape memory alloys is mainly due to the recovery of the superelastic deformation. Superelastic alloys belong to the larger family of shapememory alloys. Shape memory and superelastic alloys copper applications in innovative technology. Multiresponse optimization of wedm process parameters for. The use of superelastic shape memory alloy sma bars in the nearsurfacemounted nsm strengthening application can offer advantages such as improved bond behavior, enhanced deformation capacity, and postevent functionality. Modeling tensilecompressive asymmetry for superelastic. Composites composed of sma wires and conventional cements can overcome the mechanical weaknesses associated with tensile fractures in conventional concretes. Taylorb, jacob lubliner universita di roma tor vergata.
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