scholarly journals Design of Shape Memory Alloy Coil Spring Actuator for Improving Performance in Cyclic Actuation

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2324 ◽  
Author(s):  
Je-sung Koh
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Design Process ◽  
Mechanical Design ◽  
Design Method ◽  
Martensite Phase ◽  
Design Parameters ◽  
Coil Spring ◽  
Actuation Frequency ◽  
Maximum Shear Strain

Performance of the shape memory alloy (SMA) coil spring actuator in cyclic actuation as an artificial muscle is strongly related to the mechanical design of the coil geometry. This paper proposes a practical design method for improving the frequency and efficiency of the SMA coil spring actuator; by designing the SMA coil spring to have large index (coil diameter/wire diameter) and pitch angle (LIP), cooling characteristics can be improved (increasing the actuation frequency) and large deformation can be obtained. The LIP design process is based on the two-state static model that describes the displacement-force relationship of the SMA coil spring in two states—a fully austenite phase and a fully martensite phase. The design process gives accurate design parameters of the SMA coil spring actuator that satisfy the required stroke and force. The model of the fully martensite phase of the SMA coil that includes the stress-induced detwinning enables the use of maximum shear strain of the SMA. The design method reduces the mass of an SMA without changing the stroke and increase the power density and efficiency. The cyclic actuation experiments demonstrate that the LIP design doubles the maximum frequency of SMA coil actuator with one-sixth the mass of the non-LIP design.

Design of Shape Memory Alloy Springs With Applications in Vibration Control

1993 ◽  
Vol 115 (1) ◽  
pp. 129-135 ◽  
Author(s):  
C. Liang ◽  
C. A. Rogers
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Vibration Control ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Design Method ◽  
Control Area ◽  
Spring Constant ◽  
Damping Capacity

Shape memory alloys (SMAs) have several unique characteristics, including their Young’s modulus-temperature relations, shape memory effects, and damping characteristics. The Young’s modulus of the high-temperature austenite of SMAs is about three to four times as large as that of low-temperature martensite. Therefore, a spring made of shape memory alloy can change its spring constant by a factor of three to four. Since a shape memory alloy spring can vary its spring constant, provide recovery stress (shape memory effect), or be designed with a high damping capacity, it may be useful in adaptive vibration control. Some vibration control concepts utilizing the unique characteristics of SMAs will be presented in this paper. Shape memory alloy springs have been used as actuators in many applications although their use in the vibration control area is very recent. Since shape memory alloys differ from conventional alloy materials in many ways, the traditional design approach for springs is not completely suitable for designing SMA springs. Some design approaches based upon linear theory have been proposed for shape memory alloy springs. A more accurate design method for SMA springs based on a new nonlinear thermomechanical constitutive relation of SMA is also presented in this paper.

A Mechanical Design Framework Based on Object-Oriented Approach

1993 ◽  
Author(s):  
Taesik Jeong ◽  
Thomas P. Kicher ◽  
Ronald J. Zab
Keyword(s):  
Design Process ◽  
Mechanical Design ◽  
Design Method ◽  
Object Oriented ◽  
Object Oriented Programming ◽  
Reduction Gear ◽  
Design Framework ◽  
Design Strategies ◽  
Decomposition Approach ◽  
Automation Systems

Abstract An object-oriented programming (OOP) technique is investigated in order to develop the framework for mechanical design automation systems. A task-oriented decomposition approach is applied to conceptualize the task-object (or task-performing-object) in which common behavior and communication protocols are encapsulated [1]. Each task in the entire design process, either controlling design strategies or performing design methods, is made into an object. The design method objects are implemented using Artificial Intelligence (AI) paradigms, such as artificial neural networks and expert systems. This report explains how OOP is integrated to develop a mechanical design framework (MDF). A single reduction gear box design process was used to identify some of the general tasks involved in mechanical design process. From this process the guidelines for developing task-objects for future systems are formed. Full details of these guidelines and an implementation example in Smalltalk on a PC are available in [7].

Shape Memory Alloys in Automotive Applications

2014 ◽  
Vol 663 ◽  
pp. 248-253 ◽  
Author(s):  
Jaronie Mohd Jani ◽  
Martin Leary ◽  
Aleksandar Subic
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
External Force ◽  
Active Element ◽  
Mechanical Design ◽  
Competitive Market ◽  
Automotive Applications ◽  
Market Prices ◽  
Sma Actuators

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.

Corrugated structures reinforced by shape memory alloy sheets: Analytical modeling and finite element modeling

2018 ◽  
Vol 233 (7) ◽  
pp. 2445-2454 ◽  
Author(s):  
Maryam Koudzari ◽  
Mohammad-Reza Zakerzadeh ◽  
Mostafa Baghani
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Finite Element Modeling ◽  
Shape Memory ◽  
Smart Structure ◽  
Design Parameters ◽  
Asymmetric Mode ◽  
Element Modeling ◽  
Structure Changes

In this study, an analytical solution is presented for a trapezoidal corrugated beam, which is reinforced by shape memory alloy sheets on both sides. Formulas are presented for shape memory alloys in states of compression and tension. According to the modified Brinson model, shape memory alloys have different thermomechanical behavior in compression and tension, and also these alloys would behave differently in different temperatures. The developed formulation is based on Euler–Bernoulli theory. Deflection of the smart structure and the effect of asymmetric response in shape memory alloys are studied. Results found from the semi-analytic modeling are compared to and validated through a finite element modeling, and there is more than [Formula: see text] agreement between two solutions. With regard to the results, the neutral axis of the smart structure changes in each section. The maximum deflection ratio of asymmetric mode to symmetric one mode is 1.7. Additionally, the effect of design parameters on deflection is studied in detail.

Development of Minimal Invasive SMA Multi-Transducer Unit for Blood Analysis or Drug Delivery

2010 ◽  
Author(s):  
Hidetake Yamamoto
Keyword(s):  
Drug Delivery ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Blood Vessels ◽  
Glucose Level ◽  
Minimal Invasive ◽  
Blood Analysis ◽  
Research Purpose ◽  
Coil Spring ◽  
Action Mechanisms

This research purpose is to develop minimal medical units applying heated actuations of the Shape Memory Alloy (SMA) transducers using the medical Ti-Ni material, in order to enable minimal hypodermic invasive microvolume either blood suction or drug delivery by equipping nontoxic and minimal edged microneedle to be created in my laboratory. I have focused on lymphocytes for immunotoxin and erythrocytes for glucose level in blood. This paper has reported double-action mechanisms of the compact unit in originally developing and its actions by low DC inputs. The Joule’s heating of the SMA coil spring transducer might be useful for indenting blood vessels whose diameter was larger than the microneedle because of generating indentation stroke of 2 mm and recovery force of 0.25 N 0.6 s later from heating when applied DC 2 V and 0.5 A. When applied DC 1.5 V and 2 A, the octagonal-pyramidal foil transducer for blood suction recovered as plane condition as before octagonal-pyramidal forming 8 s later from heating.

Wet Shape Memory Alloy Actuated Robotic Heart

2009 ◽  
Author(s):  
Joel Ertel ◽  
Stephen Mascaro
Keyword(s):  
Shape Memory Alloy ◽  
Theoretical Analysis ◽  
Shape Memory ◽  
Preliminary Analysis ◽  
Design Concept ◽  
Design Parameters ◽  
Sma Actuators ◽  
Fluid Analysis ◽  
Cold Fluid ◽  
Simulation And Experiment

This paper presents a conceptual design and preliminary analysis for a biomimetic robotic heart. The purpose of the robotic heart is to distribute hot and cold fluid to robotic muscles composed of wet shape-memory alloy (SMA) actuators. The robotic heart is itself powered by wet SMA actuators. A heart design concept is proposed and the feasibility of self-sustaining motion is investigated through simulation and experiment. The chosen design employs symmetric pumping chambers for hot and cold fluid. Analysis of this design concept shows that there exists a range of design parameters that will allow the heart to output more fluid than it uses. Additionally, it is shown that the heartbeat rate decreases as the system increases in size, and that the number of actuators and their length limit the power output of the pump. Experimental results from a prototype heart agree with the predicted trends from theoretical analysis and simulation.

Enabling Variation of Manufacturing Process Parameters in Early Stages of Product Development

2006 ◽  
Author(s):  
Patrik Boart ◽  
Ola Isaksson
Keyword(s):  
Product Development ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Mechanical Design ◽  
Design Method ◽  
Local Level ◽  
Simulation Models ◽  
Design Parameters ◽  
Functional Requirements ◽  
Early Stages

Currently, mechanical design of aero engine structural components is defined by dimensioning of Design Parameters (DP's) to meet Functional Requirements (FR's). FR's are typically loads, geometrical interfaces and other boundary conditions. Parameters from downstream processes are seldom actually seen as DP's. This paper proposes that downstream process parameters are treated as DP's which calls for engineering methods that can define and evaluate these extended set of DP's. Using the proposed approach manufacturing process alternatives can be used as DP's in early stages of product development. Both the capability to quantitatively assess impact of varying manufacturing DP's, and the availability of these design methods are needed to succeed as an early phase design method. One bottleneck is the preparation time to define and generate these advanced simulation models. This paper presents how these manufacturing process simulations can be made available by automating the weld simulation preparation stages of the engineering work. The approach is based on a modular approach where the methods are defined with knowledge based engineering techniques-operating close to the CAD system. Each method can be reused and used independently of each other and adopted to new geometries. A key advantage is the extended applicability to new products, which comes with a new set of DP's. On a local level the lead time to generate such manufacturing simulation models is reduced with more than 99% allowing manufacturing process alternatives to be used as DP's in early stages of product development.

scholarly journals Optimal Design of Shape Memory Alloy Composite under Deflection Constraint

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1733 ◽  
Author(s):  
Yogesh Gandhi ◽  
Alessandro Pirondi ◽  
Luca Collini
Keyword(s):  
Optimal Design ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Optimization Problem ◽  
Edge Length ◽  
Design Parameters ◽  
Stable Configuration ◽  
Alloy Composite ◽  
Bistable Behavior ◽  
Design Variables

Shape-adaptive or morphing capability in both aerospace structures and wind turbine blade design is regarded as significant to increase aerodynamic performance and simplify mechanisms by reducing the number of moving parts. The underlying bistable behavior of asymmetric cross-ply composites makes them a suitable candidate for morphing applications. To date, various theoretical and experiential studies have been carried out to understand and predict the bistable behavior of asymmetric laminates and especially the curvature obtained in their stable configurations. However, when the bi-stable composite plate is integrated with shape memory alloy wires to control the curvature and to snap from a stable configuration to the other (shape memory alloy composite, SMAC), the identification of the design parameters, namely laminate edge length, ply thickness and ply orientation, is not straightforward. The aim of this article is to present the formulation of an optimization problem for the parameters of an asymmetric composite laminate integrated with pre-stressed shape memory alloys (SMA) wires under bi-stability and a minimum deflection requirement. Wires are modeled as an additional ply placed at the mid-plane of the composite host plate. The optimization problem is solved numerically in MATLAB and optimal design variables are then used to model the SMAC in ABAQUS™. Finite element results are compared against numerical results for validation.

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