Research and application of novel planar bending embedded shape memory alloy actuator

2007 ◽  
Vol 221 (2) ◽  
pp. 249-257 ◽  
Author(s):  
K Yang ◽  
C L Gu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
Structural Parameters ◽  
Hysteresis Loops ◽  
Response Speed ◽  
Experimental Results ◽  
Elastic Rod ◽  
Control Precision ◽  
New Type

To overcome low-response speed and low-control precision in the existing traditional shape memory alloy (SMA) actuators, a new type of structure named planar bending embedded SMA actuator was developed. Two SMA wires were embedded in parallel with the axis of the elastic rod. The recovering wire, which was superposed along rod's axis, was set to obtain ‘U’ memory shape and the restoring wire, which was placed off-axially, got straight memory shape. The differential stain gauges were located at suitable position in corresponding to the actuator's bending direction in order to measure the signal of displacement. By making use of continuity, common origin and common limit conditions, and adjusting martensite fraction coefficients appropriately, the analytical model was deduced to adequately account for the presence of major and minor hysteresis loops. The structural parameters of 60 mm long actuator, such as rod's radius, wire's radius, wire's recoverable curvature, and offset distance, were optimized by combining analytical model with experimental results. The experimental results prove the merits in optimal prototype.

Experimental characterization and control of a magnetic shape memory alloy actuator using the modified generalized rate-dependent Prandtl–Ishlinskii hysteresis model

2018 ◽  
Vol 232 (5) ◽  
pp. 506-518 ◽  
Author(s):  
Saeid Shakiba ◽  
Mohammad Reza Zakerzadeh ◽  
Moosa Ayati
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Excitation Frequency ◽  
Hysteresis Loops ◽  
Experimental Results ◽  
Hysteretic Behavior ◽  
Magnetic Shape Memory ◽  
Shape Memory Alloy Actuator ◽  
Rate Dependent ◽  
Magnetic Shape Memory Alloy

In this article, two models are used, namely rate-independent and rate-dependent generalized Prandtl–Ishlinskii, to characterize a magnetic shape memory alloy actuator. The results show that the rate-independent model cannot consider the effect of input excitation frequency, while the rate-dependent model omits this drawback by defining a time-dependent operator. For the first time, the effects of excitation frequency on the hysteretic behavior of magnetic shape memory alloy actuator are investigated. In this study, five excitation voltages with different frequencies in the range of 0.05–0.4 Hz are utilized as inputs to the magnetic shape memory alloy actuator and the displacement outputs are measured. Experimental results indicate that, with increasing the excitation frequency, the size of the hysteresis loops changes. Since the generalized rate-dependent Prandtl–Ishlinskii model cannot consider the asymmetric hysteresis loops, in the developed model, a tangent hyperbolic function is applied as an envelope function in order to improve the capability of the model in characterizing the asymmetric behavior of magnetic shape memory alloy actuator. The parameters of both rate-dependent and rate-independent models are identified by genetic algorithm optimization. The results reveal that the rate-independent form is not capable of accurately describing the hysteretic behavior of magnetic shape memory alloy actuator for different input frequencies. Simulation and experimental results also demonstrate the proficiency of the developed model for precise characterization of the saturated rate-dependent hysteresis loops of magnetic shape memory alloy actuator. In addition, the proposed model is utilized for determining a proper range for controller coefficients during controller design.

Research on novel shape memory alloy multi-fingered humanoid hand

2007 ◽  
Vol 221 (9) ◽  
pp. 1131-1140 ◽  
Author(s):  
K Yang ◽  
C L Gu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Structural Parameters ◽  
Human Beings ◽  
Statistical Research ◽  
Offset Distance ◽  
Maximum Angle ◽  
Output Force ◽  
New Type ◽  
Humanoid Hand

Two new type actuators named planar bending embedded shape memory alloy actuator (ESMAA) and spacial bending ESMAA were presented. Using shape memory effect of SMA wires and elasticity of room temperature vulcanization silicone rubber, the ESMAAs could output force and bend displacement steadily. Furthermore, a novel three-fingered humanoid robot hand consisting of six ESMAAs was developed first. The structural parameters of the actuators, such as rod's radius, wire's radius, wire's recoverable curvature, and offset distance were optimized by combining analytical model with experimental results. On the basis of bionics, the lengths of hand's knuckles were determined through statistical research on the configuration of human beings' hands. The locations of fingers were carefully chosen through a volume optimal index. It is shown in the experiments that maximum angle between ends' tangents of each finger are 68.5°, 79°, and 79°, respectively. The tip of each finger could reach its final position approximately at the same time and by controlling the bending of each finger, the hand could accomplish fine manipulation like that of a human being.

Investigation of a shape memory alloy releasable mechanism applied in space environment

2020 ◽  
Vol 64 (1-4) ◽  
pp. 393-401
Author(s):  
Kan Bian ◽  
Chunhua Zhou ◽  
Fagang Zhao ◽  
Yipeng Wu ◽  
Ke Xiong
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Response Speed ◽  
Space Environment ◽  
Maintenance Cost ◽  
Heating Efficiency ◽  
Output Force ◽  
Maximal Output ◽  
New Type ◽  
Sma Spring

Though the conventional pyrotechnic fastener mechanisms are widely used in spacecraft for their reliable releasable-fastening function, they still have several unavoidable problems: physical shock, high maintenance cost, to name a few. This paper introduces a new type of smart releasable mechanism based on a Shape Memory Alloy (SMA) spring and its corresponding heating apparatus. To obtain the high heating efficiency and increase the response speed, the SMA spring is transitionally fit with the heating apparatus shell instead of directly heating by electric current. As soon as the heating apparatus begins to work, the SMA spring will provide an un-locking force to release the fastening device within the standard time, which also realizes the similar releasable-fastening function comparing with the conventional pyrotechnic fastener mechanisms. In order to ensure the reliability of space products, the heating apparatus is composed of two identical ceramic heating elements which can be controlled independently or synchronously. Finally, the experimental results clearly show that, under the satellite power supply at the constant value of 28 V, the SMA spring can reach the desired 30 N unlocking force within 93 s and 51 s by single or dual heating elements, respectively. The maximal output force can even be increased as large as 40 N under the limited volume of the releasable mechanism.

Compensation of Hystetresis Nonlinearties in Smart Actuators

2008 ◽  
Author(s):  
Mohammad Al Janaideh ◽  
Subash Rkaheja ◽  
Chun-Yi Su
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Hysteresis Loops ◽  
Experimental Results ◽  
Piezoceramic Actuator ◽  
Sma Actuators ◽  
Smart Actuators ◽  
Play Operator

Smart actuators such shape memory alloy (SMA) actuators and piezoceramic actuators exhibit different hysteresis loops. In this paper, a generalized Prandtl-Ishlinskii model is utilized for modeling and compensation of hysteresis effects in smart actuators. In the formulated model, a generalized play operator together with a density is integrated to form the generalized Prandtl-Ishlinskii model. The capability of the formulated model to characterize hysteresis in smart actuators is demonstrated by comparing its outputs with experimental results obtained from different smart actuators. Furthermore, an analytical inverse of the generalized Prandtl-Ishlinskii model is derived for compensations in different smart actuators. Such compensation is experimentally illustrated by piezoceramic actuator.

scholarly journals Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

10.5772/7228 ◽  
2009 ◽  
Vol 6 (3) ◽  
pp. 29 ◽  
Author(s):  
Hu Bing-Shan ◽  
Wang Li-Wen ◽  
Fu Zhuang ◽  
Zhao Yan-zheng
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
Basic Structure ◽  
Thin Elastic Plate ◽  
Climbing Robots ◽  
Suction Cup ◽  
Sma Actuator ◽  
Suction Cups ◽  
Pressure Suction

Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA) are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME) extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

Research of Ni-Mn-Ga Shape Memory Alloy Based Mechanical Vibration Detection Device

2014 ◽  
Vol 1006-1007 ◽  
pp. 845-848
Author(s):  
Yong Zhi Cai
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Vibration ◽  
Vibration Signal ◽  
Experimental Results ◽  
Vibration Measurements ◽  
Vibration Detection ◽  
Vibration Sensing

The study explores the vibration sensing effect of Ni-Mn-Ga shape memory alloy, based on the experimental results, researched the characteristics of this alloy applied in mechanical vibration signal sensors, and describes the feasibility of this alloy used for vibration measurements.

A simplified analytical model to simulate martensite reorientation and plasticity in shape memory alloy ring couplers

2021 ◽  
pp. 1045389X2110572
Author(s):  
Fabrizio Niccoli ◽  
Valentina Giovinco ◽  
Cedric Garion ◽  
Carmine Maletta ◽  
Paolo Chiggiato
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
High Vacuum ◽  
Ring Expansion ◽  
Particle Accelerators ◽  
European Organization ◽  
Elastic Plastic ◽  
Wide Range ◽  
Martensite Reorientation

Recent studies on Shape Memory Alloy rings have been undertaken at the European Organization for Nuclear Research (CERN) to develop smart and leak-tight couplers for Ultra High Vacuum systems of particle accelerators. A special thermo-mechanical process (training) is needed to provide SMA rings with proper functional properties, that is to allow thermal mounting, dismounting, and leak tight coupling within a given service temperature window. Low temperature ring expansion is a crucial part of the training process as it gives suitable size, shape recovery properties, and thermal stability range to the SMA element. An analytical model, based on simplified elastic-plastic axisymmetric concepts, has been developed and implemented in a commercial software to simulate isothermal SMA rings expansions. It is particularly useful to predict the final size of a martensitic SMA coupler as a function of the initial dimensions and of the pre-deformation parameters. The effectiveness of the model has been demonstrated by analyzing the stress/deformation field occurring in a wide range of ring geometries for different load cases including martensite reorientation and plasticity. The predictions of the analytical model have been systematically compared with those obtained by axisymmetric finite element (FE) analyses based on elastic-plastic constitutive models and experimental measurements.

Research on Walking Mechanism Base on Biological Metal Fibre

2013 ◽  
Vol 785-786 ◽  
pp. 1267-1272
Author(s):  
Shi Ju E ◽  
Xuan Zhong Ding
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Trajectory Planning ◽  
New Type ◽  
Simulation Results ◽  
Metal Fibre ◽  
Walking Mechanism

A new walking mechanism base on biological metal fibre is study in the paper. It used a new type of shape memory alloy (biological metal fibre, BMF) as actuator. The multilegged walking mechanism is employ and study. Its mobile mechanism and trajectory planning is analysed so as to achieve miniaturization goals. The simulation results showed that the multilegged walking mechanism could be effectively driven by the actuator base on BMF.

Simulation on Uniaxial-Tension Behavior of NiTi Shape Memory Alloy Films

2009 ◽  
Vol 79-82 ◽  
pp. 1209-1212
Author(s):  
Shuang Shuang Sun ◽  
Jing Dong
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Uniaxial Tension ◽  
Theoretical Foundation ◽  
Quantitative Description ◽  
Experimental Results ◽  
Niti Shape Memory Alloy ◽  
Alloy Films ◽  
Actuation Mechanism ◽  
Micro Actuators

Based on experimental results reported in the reference, Liang-Rogers’ constitutive model for SMA is used to simulate the stress-strain curves of NiTi shape memory alloy films under uniaxial tension with isothermal conditions. The effects of film compositions and temperature on the tensile behavior of NiTi shape memory alloy films are discussed. By comparing the simulation results with the experimental results, it is found that the simulation curves agree basically with the experimental curves except that the phase-transformation regions are wider in the simulation curves. This demonstrates that the Liang-Rogers’ model can be used to predict the thermomechanical behavior of shape memory alloy films roughly. This study provides some theoretical foundation for the quantitative description and prediction of the actuation mechanism when shape memory alloy films are used as micro-actuators.

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