Computer-Aided Development of Shape Memory Actuators as an Approach Towards a Standardized Developing Method

2011 ◽  
Author(s):  
Horst Meier ◽  
Alexander Czechowicz
Keyword(s):  
Numerical Model ◽  
Shape Memory ◽  
Smart Materials ◽  
Fatigue Behavior ◽  
Design Tool ◽  
Thermally Activated ◽  
Shape Memory Actuators ◽  
Computer Aided ◽  
Actual Shape ◽  
Developing Method

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 (lightweight-actuators, lower costs…etc.) these elements are only seldom integrated by engineers into mechatronical systems. The reason for this phenomenon is the insufficiently described dynamic behavior, especially at different boundary conditions. Also the lack of empirical data (like fatigue behavior and thermal balances) is a reason why development projects with shape memory actuators lead often to failures. Therefore a need of developing methods, standardized testings of empirical properties and computer aided actuator development systems is motivated. Based on an analysis of energy fluxes into and out of the actuator, a numerical model, implemented in MATLAB/SIMULINK is presented. The numerical model includes also a configuration and design tool which allows simulating different solutions to a problem. Additionally, this paper describes a development method for SMA which is fitted to uniqueness of these smart materials. In conclusion, this paper compares the conventional developing process to the presented method applying a mechatronical SMA-device.

A Multi-Purpose Method for SMA Actuator Development

2013 ◽  
Author(s):  
Sven Langbein ◽  
Alexander Czechowicz
Keyword(s):  
Standardized Testing ◽  
Shape Memory ◽  
Smart Materials ◽  
Research Work ◽  
Simulation Tools ◽  
Sma Actuators ◽  
Shape Memory Actuators ◽  
Computer Aided ◽  
Sma Actuator ◽  
Actual Shape

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.

On the Functional Characteristics of Adaptive Resetting of Shape Memory Actuators in the Field of Automotive Applications

2012 ◽  
Author(s):  
Alexander Czechowicz ◽  
Sven Langbein
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Problem Definition ◽  
Ambient Temperatures ◽  
Automotive Systems ◽  
Thermally Activated ◽  
Shape Memory Actuators ◽  
Methodical Approach ◽  
Long Time ◽  
Actual Shape

Shape memory alloys (SMA) are thermally activated smart materials. Due to their ability to change into a previously imprinted actual shape by means of thermal activation, they are suitable as actuators for mechatronical systems. Despite the advantages shape memory alloy actuators provide (lightweight-actuators, lower costs etc.), these elements are seldom integrated by engineers into automotive systems. One reason for this phenomenon is among others the varying dynamic behavior at different ambient temperatures. A methodical approach through the problem definition as well as the presentation of different solutions using adaptive resetting introduces experimental results on the behavior of these actuator systems. The publication presents different solutions as well as long-time experiments compared to conventional SMA actuators at automotive conditions.

Experimental Validation and Numerical Simulation of Shape Memory Flat Wire Actuators

2014 ◽  
Author(s):  
Alexander Czechowicz ◽  
Sven Langbein
Keyword(s):  
Shape Memory Alloy ◽  
Boundary Conditions ◽  
Shape Memory ◽  
Smart Materials ◽  
Empirical Data ◽  
Dynamic Properties ◽  
Fatigue Behavior ◽  
Different Boundary Conditions ◽  
Heating And Cooling ◽  
Actual Shape

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.

Adaptive Elastic SMA Elements for Damping Applications

2013 ◽  
Author(s):  
Alexander Czechowicz ◽  
Peter Dültgen ◽  
Sven Langbein
Keyword(s):  
Boundary Conditions ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Electrical Resistance ◽  
Thermal Activation ◽  
Hysteretic Behavior ◽  
Damping Function ◽  
Actual Shape ◽  
Elastic Elements

Shape memory alloys (SMA) are smart materials, which have two technical usable effects: While pseudoplastic SMA have the ability to change into a previously imprinted actual shape through the means of thermal activation, pseudoelastic SMA show a reversible mechanical elongation up to 8% at constant temperature. The transformation between the two possible material phases (austenite and martensite) shows a hysteretic behavior. As a result of these properties, SMA can be used as elastic elements with intrinsic damping function. Additionally the electrical resistance changes remarkably during the material deformation. These effects are presented in the publication in combination with potential for applications in different branches at varying boundary conditions. The focus of the presented research is concentrated on the application of elastic elements with adaptive damping function. As a proof for the potential considerations, an application example sums up this presentation.

The Role of Shape Memory Alloys in Smart/Adaptive Structures

1991 ◽  
Vol 246 ◽  
Author(s):  
L. McD. Schetky
Keyword(s):  
Composite Materials ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Dynamic Characteristics ◽  
Smart Materials ◽  
Acoustic Radiation ◽  
Sensors And Actuators ◽  
Adaptive Structures ◽  
Distributed Sensors ◽  
Shape Memory Actuators

AbstractAdaptive structures, also called Intelligent or smart materials, refers to the various materials systems which automatically or remotely alter their dynamic characteristics or their geometry to meet their Intended performance. By integrating the sensors and actuators Into the structural system, typically a composite materials, control of shape, vibration and acoustic behavior an be effected. In addition to active control, passive control of system damping can be achieved in these structures. The sensors employed include piezoelectric ceramics, piezoelectric polymer films, ferroelectrics, and fiber optics. For producing the stress induced changes in dynamic characteristics of a composite the actuators are either embedded within the composite or are surface mounted. In general, the piezoelectric type actuator Is used where small strains at high frequencies are appropriate, while shape memory actuators are used when high forces and strains at lower frequencies are required. Static damping, modulus shift effect on acoustic radiation, and strain energy shift of modal response and acoustic radiation of composite materials with embedded shape memory actuators will be discussed. The constitutive equations for shape memory alloys will be described and how these are used in the design of adaptive composite structuresThe term smart materials seems to have become a part of the engineering vocabulary with variants such as Intelligent materials, and their application in adaptive structures. Smart materials consist of a structural component such as a composite such as fiber reenforced resin, with distributed sensors and actuators and a microprocessor. In response to changing external or Internal conditions these materials can change their properties to more effectively perform their function. The external conditions may be environment such as light or heat, loads, vibration or the need to change the geometry or shape of the structure to cope with changing service conditions. Internal conditions may be delamination in a composite, fatigue cracks in a metallic or nonmetallic structure, or other forms of Incipient failure.In reviewing papers presented in the past several years at conferences on smart/adaptive structures one would see a dominant number on various aspects of space structures such as mirrors. antennas, robotics booms and satellite docking. In these areas the control of vibration or the precise control of motion are most often the specific subject addressed. Much of the ongoing research is on control theory and the design of algorithms to define the sensor-actuator-microprocessor Integration. Of concern in this paper Is the actuator itself which, in response to commands from the microprocessor, produces strains and forces in the structure to modify Its acoustic or vibratory response or alter Its shape. These actuators are broadly of two types: low to medium force, low strain, high frequency systems, typically a piezoceramic such as PZT, or a high force, high strain, low frequency actuator which is most likely to be a shape memory alloy element.

scholarly journals OPTIMIZATION OF NICKEL CONTENT ON SOME PROPERTIES OF (NITI) SHAPE MEMORY ALLOY

2020 ◽  
Vol 1 (01) ◽  
pp. 40-47
Author(s):  
Aissa Bouaissi ◽  
Nabaa S Radhi ◽  
Karrar F. Morad ◽  
Mohammad H. Hafiz ◽  
Alaa Abdulhasan Atiyah
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Smart Materials ◽  
Shape Recovery ◽  
Fatigue Behavior ◽  
Nickel Content ◽  
Functionally Graded ◽  
Niti Shape Memory Alloy ◽  
Shape Effect ◽  
The Impact

Shape Memory Alloys (SMAs) are one of the most hopeful smart materials, especially, Nickel–Titanium (NiTi or Nitinol). These alloys are great and desirable due to their excellent reliability and behavior among all the commercially available alloys. In addition, strain recovery, (Ni–Ti) is granulated for a wide variety of medical uses because of its favorite properties such as fatigue behavior, corrosion resistance and biocompatibility. This paper explores the creation and the characterization of functionally graded (NiTi) materials. This work demonstrations the impact of Nickel contains changes on the characteristics of NiTi shape memory alloy, in order to obtain the suitable addition of Nickel contain, which gives the optimal balance between hardness, start and finish martensitic point, shape recovery and shape effect of alloys properties. These materials are prepared to obtain suddenly or gradually microstructure or composition differences inside the structure of one piece of material, the specimens made by powder metallurgy process and the influence of every layer of composite by; micro-hardness, transformation temperature DSC and shape effect. The hardness value and shape recovery decrease with increase nickel content. superior shape memory effect (SME) and shape recovery (SR) properties (i.e., 8.747, 10.270 for SMA-FGM1 SMA-FGM2 respectively, and SR is 1.735, 2.977 for SMA-FGM1 SMA-FGM2) respectively.  

High Speed Shape Memory Alloy Activation

2012 ◽  
Author(s):  
Alexander Czechowicz ◽  
Jonas Böttcher ◽  
Sebastian Mojrzisch ◽  
Sven Langbein
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
High Speed ◽  
Industrial Applications ◽  
Feedback Signal ◽  
Sma Actuators ◽  
Wide Range ◽  
Current Activation ◽  
Actual Shape ◽  
Control Feedback

Due to their ability to change into a previously imprinted actual shape through the means of thermal and electrical activation, shape memory alloys (SMA) are suitable as actuators. To apply these smart materials to a wide range of high-speed applications like valves or safety systems, an analysis of the application potential is required. The detection of inner electrical resistance of SMA actuators allows gauging the actuator’s stroke. By usage of a microcontroller a smart system without any hardware sensors can be realized which protects the system from overheating during high-current activation. The publication concentrates on different experimental data on high-speed actuation under 20ms and the potentials in the field of industrial applications. The paper gives an overview about different controlling methods for SMA-actuators, experiments concerning the resistance behavior of SMA and the development of systems using a resistance control feedback signal during high-speed activation.

Cu-AI based single crystal shape memory actuators and drives

2003 ◽  
Vol 112 ◽  
pp. 1181-1184 ◽  
Author(s):  
I. Vahhi ◽  
S. Pulnev ◽  
A. Priadko
Keyword(s):  
Single Crystal ◽  
Shape Memory ◽  
Crystal Shape ◽  
Shape Memory Actuators
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