Spool-packaging of shape memory alloy actuators: Performance model and experimental validation

2012 ◽  
Vol 23 (2) ◽  
pp. 201-219 ◽  
Author(s):  
John A Redmond ◽  
Diann Brei ◽  
Jonathan Luntz ◽  
Alan L Browne ◽  
Nancy L Johnson

Shape memory alloy (SMA) actuators in the wire form are attractive because of their simplistic architecture and electrical operation, and their manufacturability at high yields and low cost. While SMA actuators are known for their superior work density among smart materials, packaging long lengths of SMA wire needed for moderate to large motions is an ongoing technical challenge. This article investigates spooling as a packaging approach to provide more compact actuator footprints. An analytical, quasi-static model is derived to provide a foundational tool for the analysis and synthesis of spool-packaged SMA wire actuators. The model predicts motion with respect to a generalized architecture, and specifiable geometric, material, and loading parameters. The model prediction accounts for the effects of local friction loss and bending strains, and for a “binding” limitation due to accumulated friction. An experimental validation study demonstrates the model’s ability to predict actuator motion well in terms of form and magnitude with respect to load and packaging geometry. This model provides a basis for a systematic application of spooled-packaging techniques to overcome packaging limitations of SMA, positioning SMA wire actuators as a viable alternative in many applications.

2017 ◽  
Vol 380 ◽  
pp. 212-217 ◽  
Author(s):  
C.A. Araújo Mota ◽  
C.J. Araújo ◽  
A.G. Barbosa de Lima ◽  
Tony Herbert Freire de Andrade ◽  
D. Silveira Lira

SMART materials have gained several applications in industries, especially aeronautical and biomedical. Therefore, the fabrication process of these materials must present quality in the completion and dimensioning, in addition to well established mechanical properties. In this sense, the Resin Transfer Molding (RTM) process is presented as an alternative to the manufacture of such products. This process presents advantages compared to other methods, such as, product quality and low cost. Thus, this work aims to model and simulate numerically the manufacturing process of polymer composite reinforced with NiTi shape memory alloy by RTM using the Ansys CFX commercial software. Results of pressure, velocity and volume fractions fields of the phases are presented and discussed. It was verified that the process parameters, like injection pressure and resin inlet and air outlet positions influenced the total time of the process and final product quality.


Author(s):  
Alexander Czechowicz ◽  
Sven Langbein

Shape memory alloys (SMA) are thermally activated smart materials. Due to their ability to change into a previously imprinted actual shape through the means of thermal activation, they are suitable as actuators for mechatronical systems. Despite of the advantages shape memory alloy actuators provide, these elements are only seldom integrated by engineers into mechatronical systems. Reasons are the complex characteristics, especially at different boundary conditions and the missing simulation- and design tools. Also the lack of knowledge and empirical data are a reason why development projects with shape memory actuators often lead to failures. This paper deals with the dynamic properties of SMA-actuators (Shape Memory Alloy) — characterized by their rate of heating and cooling procedures — that today can only be described insufficiently for different boundary conditions. Based on an analysis of energy fluxes into and out of the actuator, a numerical model of flat-wire used in a bow-like structure, implemented in MATLAB/SIMULINK, is presented. Different actuation parameters, depending on the actuator-geometry and temperature are considered in the simulation in real time. Additionally this publication sums up the needed empirical data (e.g. fatigue behavior) in order to validate the numerical two dimensional model and presents empirical data on SMA flat wire material.


Author(s):  
Md Mehedi Hasan ◽  
Theocharis Baxevanis

Shape Memory Alloy (SMA)-actuators are efficient, simple, and robust alternatives to conventional actuators when a small volume and/or large force and stroke are required. The analysis of their failure response is critical for their design in order to achieve optimum functionality and performance. Here, (i) the existing knowledge base on the fatigue and overload fracture response of SMAs under actuation loading is reviewed regarding the failure micromechanisms, empirical relations for actuation fatigue life prediction, experimental measurements of fracture toughness and fatigue crack growth rates, and numerical investigations of toughness properties and (ii) future developments required to expand the acquired knowledge, enhance the current understanding, and ultimately enable commercial applications of SMA-actuators are discussed.


2018 ◽  
Vol 30 (3) ◽  
pp. 479-494 ◽  
Author(s):  
Venkata Siva C Chillara ◽  
Leon M Headings ◽  
Ryohei Tsuruta ◽  
Eiji Itakura ◽  
Umesh Gandhi ◽  
...  

This work presents smart laminated composites that enable morphing vehicle structures. Morphing panels can be effective for drag reduction, for example, adaptive fender skirts. Mechanical prestress provides tailored curvature in composites without the drawbacks of thermally induced residual stress. When driven by smart materials such as shape memory alloys, mechanically-prestressed composites can serve as building blocks for morphing structures. An analytical energy-based model is presented to calculate the curved shape of a composite as a function of force applied by an embedded actuator. Shape transition is modeled by providing the actuation force as an input to a one-dimensional thermomechanical constitutive model of a shape memory alloy wire. A design procedure, based on the analytical model, is presented for morphing fender skirts comprising radially configured smart composite elements. A half-scale fender skirt for a compact passenger car is designed, fabricated, and tested. The demonstrator has a domed unactuated shape and morphs to a flat shape when actuated using shape memory alloys. Rapid actuation is demonstrated by coupling shape memory alloys with integrated quick-release latches; the latches reduce actuation time by 95%. The demonstrator is 62% lighter than an equivalent dome-shaped steel fender skirt.


Author(s):  
Sven Langbein ◽  
Alexander Czechowicz

Shape memory alloys (SMA) are thermally activated smart materials. Due to their ability to change into a previously imprinted actual shape through the means of thermal activation, they are suitable as actuators for mechatronical systems. Despite of the advantages shape memory alloy actuators provide, these elements are only seldom integrated by engineers into mechatronical systems. Reasons are the complex characteristics, especially at different boundary conditions and the missing simulation- and design tools. Also the lack of knowledge and empirical data are a reason why development projects with shape memory actuators often lead to failures. Therefore, a need of developing methods, standardized testing of empirical properties and computer aided simulation tools is motivated. While computer-aided approaches have been discussed in further papers, as well as standardization potentials of SMA actuators, this paper focuses on a developing method for SMA actuators. The main part of the publication presents the logical steps which have to be passed, in order to develop an SMA actuator, considering several options like mechanical, thermal, and electrical options. As a result of the research work, the paper proves this method by one example in the field of SMA-valve technology.


2018 ◽  
Vol 21 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Enrique Soriano-Heras ◽  
Fernando Blaya-Haro ◽  
Carlos Molino ◽  
José María de Agustín del Burgo

1999 ◽  
Author(s):  
Jian Sun ◽  
Ali R. Shahin

Abstract This paper investigates robust control problem of structural vibrations using shape memory alloy (SMA) wires as actuators. The mathematical model for these SMA actuators is derived with emphasis in model uncertainty. The linearization of the relation between stress and temperature dynamics of SMA actuators is analyzed for active control. To handle the uncertainties caused by the linearization and the neglected high frequency dynamics, optimal H∞ control was employed to design a controller. An example is used to demonstrate the design procedures and the control system is tested in a nonlinear environment.


2021 ◽  
Vol 1019 ◽  
pp. 3-11
Author(s):  
Niranjan Pattar ◽  
S.F. Patil ◽  
Pratik Patil ◽  
Iranna Anikivi ◽  
Shridhar Hiremath

Embedding smart materials in the composite to enhance mechanical strength have become a research hotspot owing to their unique properties. The present research also focus on novel way to fabricate composite by embedding Shape Memory Alloy (SMA) wire and montmorillonite (MMT) nanoclay by varying clay concentration (0-7 wt.%). The extent of dispersion of nanoclay in epoxy resin was studied using Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD). Fabricated samples were examined for tensile, flexural and impact characteristics. Scanning Electron Microscopy (SEM) was used to study the adhesion, delamination and damage occurred within the composite due to tensile loading. Results shows that the tensile strength, flexural strength and impact energy of SMA/MMT/glass/epoxy composite was improved by 23%, 21% and 57% respectively, when it was compared with composite with glass/epoxy composite.


Author(s):  
S Farzaneh Hoseini ◽  
S Ali MirMohammadSadeghi ◽  
Alireza Fathi ◽  
Hamidreza Mohammadi Daniali

Shape memory alloys are among the highly applicable smart materials that have recently appealed to scientists from various fields of study. In this article, a novel shape memory alloy actuator, in the form of a rod, is introduced, and an adaptive model predictive control system is designed for position control of the developed actuator. The need for such an advanced control system emanates from the fact that modeling and controlling of shape memory alloy actuators are thwarted by their hysteresis nonlinearity, dilatory response, and high dependence on environmental conditions. Real-time identification and dynamic parameter estimation of the model are addressed according to orthogonal Laguerre functions and recursive least square algorithm. In the end, the designed control system is implemented on the experimental setup of the fabricated shape memory alloy actuator. It is observed that the designed control system successfully tracks the variable step and sinusoidal control references with startling accuracy of ±1 μm.


2014 ◽  
Vol 663 ◽  
pp. 248-253 ◽  
Author(s):  
Jaronie Mohd Jani ◽  
Martin Leary ◽  
Aleksandar Subic

Shape memory alloy (SMA) actuators have drawn much attention and interest due to their unique and superior properties, and are expected to be equipped in many modern vehicles at competitive market prices. The key advantage is that SMA actuators do not require bulky and complicated mechanical design to function, where the active element (e.g. SMA wire or spring) can be deformed by applying minimal external force and will retain to their previous form when subjected to certain stimuli such as thermomechanical or magnetic changes. This paper describes the SMA attributes that make them ideally suited as actuators in automotive applications and to address their limitations, feasibilities and prospects.


Sign in / Sign up

Export Citation Format

Share Document