Mechanical Deformation of Field-Coupled Materials

2002 ◽  
Author(s):  
Pavel M. Chaplya ◽  
Geoffrey P. McKnight ◽  
Gregory P. Carman
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Residual Strain ◽  
Applied Load ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Mechanical Deformation ◽  
Passive Damping ◽  
Wide Range ◽  
Internal States

This article describes remarkable similarities in the nonlinear mechanical response of different active/smart materials despite fundamental differences in the underlying mechanisms associated with each material. Active/smart materials (i.e., piezoelectric (PZT-5H), magnetostrictive (Terfenol-D), and shape memory alloys (NiTi)) exhibit strong non-linear mechanical behavior produced by changing non-mechanical internal states such as polarization, magnetization, and phase/twin configuration. In active/smart materials the initial deformation proceeds linearly followed by a jump in strain associated with the transformation of an internal non-mechanical state. After the transformation, the mechanical response returns to linear elastic. Upon unloading, a residual strain is observed which can be recovered with the application of a corresponding external field (i.e., electric, magnetic, or thermal). Due to coupling between applied fields and non-mechanical internal states, mechanical deformation is also a function of applied external fields. At a critical applied field, the residual strain is eliminated, providing repeatable cyclic characteristics that can be used in passive damping applications. Even though different intrinsic processes (i.e., polarization, magnetization, and phase/twin variant composition) govern the deformation of each material, their macroscopic behavior is explained using a unified volume fraction concept. That is, the deformation of piezoelectric material is described in terms of the volume fraction of ferroelectric domains with polarization parallel or orthogonal to the applied load; the deformation of magnetostrictive materials is described in terms of the volume fraction of magnetic domains with magnetization parallel or orthogonal to the applied load; and the deformation of shape memory material is described in terms of the volume fraction of twin variants that are oriented favorably to the applied load. Although the qualitative behavior of each material is similar, the average magnitude of stress required to induce non-linearity varies from ~10 MPa for Terfenol-D to ~65 MPa for PZT-5H to ~300 MPa for NiTi shape memory alloy. It is hypothesized that a composite material made of these materials connected in series would exhibit passive damping over a wide range of applied stress.

scholarly journals Shape-Memory Polymeric Artificial Muscles: Mechanisms, Applications and Challenges

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4246 ◽  
Author(s):  
Yujie Chen ◽  
Chi Chen ◽  
Hafeez Ur Rehman ◽  
Xu Zheng ◽  
Hua Li ◽  
...  
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Recent Progress ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Artificial Muscles ◽  
Linkage Design ◽  
Wide Range ◽  
Liquid Crystal Elastomers ◽  
Made In

Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via Tm or Tg, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes. Recently, significant achievements have been made in fabrication, modelling, and manipulation of SMP-based artificial muscles. This paper presents a review of the recent progress in shape-memory polymer-based artificial muscles. Here we focus on the mechanisms of SMPs, applications of SMPs as artificial muscles, and the challenges they face concerning actuation. While shape-memory behavior has been demonstrated in several stimulated environments, our focus is on thermal-, photo-, and electrical-actuated SMP artificial muscles.

RECENT PROGRESSES IN POLYMERIC SMART MATERIALS

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2351-2356 ◽  
Author(s):  
YAN-JU LIU ◽  
XIN LAN ◽  
HAI-BAO LU ◽  
JIN-SONG LENG
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Strain Energy Function ◽  
Electroactive Polymer ◽  
Electrically Conductive ◽  
Wide Range ◽  
Polymer Actuator ◽  
Analysis Of Stability

Smart materials can be defined as materials that sense and react to environmental conditions or stimuli. In recent years, a wide range of novel smart materials have been developed in biomaterials, sensors, actuators, etc. Their applications cover aerospace, automobile, telecommunications, etc. This paper presents some recent progresses in polymeric smart materials. Special emphasis is laid upon electroactive polymer (EAP), shape memory polymer (SMP) and their composites. For the electroactive polymer, an analysis of stability of dielectric elastomer using strain energy function is derived, and one type of electroactive polymer actuator is presented. For the shape memory polymer, a new method is developed to use infrared laser to actuate the SMP through the optical fiber embedded within the SMP. Electrically conductive nanocarbon powders are utilized as the fillers to improve the electrical conductivity of polymer. A series of fundamental investigations of electroactive SMP are performed and the shape recovery is demonstrated.

Powder Metallurgy of Nanostructured High Strength Materials

2007 ◽  
Vol 534-536 ◽  
pp. 1405-1408 ◽  
Author(s):  
Jürgen Eckert ◽  
S. Scudino ◽  
P. Yu ◽  
C. Duhamel
Keyword(s):  
Powder Metallurgy ◽  
Deformation Behavior ◽  
Volume Fraction ◽  
High Strength ◽  
Mechanical Deformation ◽  
Intrinsic Properties ◽  
Mechanical Attrition ◽  
Wide Range ◽  
Multi Phase ◽  
Strength And Ductility

Nanostructured or partially amorphous Al- and Zr-based alloys are attractive candidates for advanced high-strength lightweight materials. The strength of such materials is often 2 – 3 times higher than the strength of commercial crystalline alloys. Further property improvements are achievable by designing multi-phase composite materials with optimized length scale and intrinsic properties of the constituent phases. Such alloys can be prepared by quenching from the melt or by powder metallurgy using mechanical attrition techniques. This paper focuses on mechanically attrited powders containing amorphous or nano-(quasi)crystalline phases and on their consolidation into bulk specimens. Selected examples of mechanical deformation behavior are presented, revealing that the properties can be tuned within a wide range of strength and ductility as a function of size and volume fraction of the different phases.

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.

scholarly journals Biopolymers and its application as electroactive polymers

2021 ◽  
Vol 83 (1) ◽  
pp. 270-277
Author(s):  
Rigel Antonio Olvera Bernal ◽  
M. V. Uspenskaya ◽  
R. O. Olekhnovich
Keyword(s):  
Smart Materials ◽  
Mechanical Response ◽  
Low Cost ◽  
Electroactive Polymers ◽  
Fast Response ◽  
High Energy ◽  
High Energy Density ◽  
Compact Size ◽  
Wide Range ◽  
Electrical Stimuli

Smart materials are a group of materials that exhibit the ability to change their composition or structure, their electrical and/or mechanical properties, or even their functions in response to an external stimulus such as heat, light, electricity, pressure, etc. Some of the advantages of these materials are: lightweight, flexibility, low cost of production, high energy density, fast response and compact size. One of the promises in the area of smart materials can be found in “smart polymer”. Polymers have many attractive characteristics, such as: lightweight, inexpensiveness, fractures tolerant, and pliable. Furthermore, they can be configured into almost any conceivable shape and their properties can be tailored according to the required needs. The capability of electroactive polymers (EAPs) to respond to electrical stimuli with a mechanical response, is attracting the attention of the scientific community from a wide range of disciplines. Biopolymers in recent decades have been studied as potential electroactive materials. These groups of polymers are extracted from a natural source; thus, they are eco-friendly, additionally they stand as a cheaper solution for the development of smart materials.The present manuscript will explore some of its applications as EAPs.

scholarly journals A Review Of Utilizing Shape Memory Alloy In Structural Safety

2020 ◽  
Vol 19 (3) ◽  
pp. 116-125
Author(s):  
Abul Hasnat ◽  
Safkat Tajwar Ahmed ◽  
Hafiz Ahmed
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Smart Materials ◽  
Large Scale ◽  
Civil Engineering ◽  
Structural Safety ◽  
Damping Capacity ◽  
Engineering Structures ◽  
Structural Deterioration ◽  
Wide Range

Abstract- The advancement of material technology has paved the way for smart materials to emerge in the civil engineering sector. These smart materials possess the potential to encounter structural deterioration. Therefore, proper attention should be provided to smart materials regarding both research and application. Shape memory alloy (SMA) is a unique smart material that demonstrates growing applicability in numerous sectors. Recently, a lot of emphasis is being given to SMA research with a view to utilizing SMA in civil engineering structures. SMAs have some special properties such as high damping capacity, self-centering mechanism, two-way memory, self-adaptability etc. for which they can be used to make various types of structural control devices. An integrated assessment of the fundamental properties of SMAs, based on the existing data is presented by this paper in a concise and graphical manner. This paper also discusses the possibility of implementing SMAs in a wide range of civil engineering application, therefore motivating the large scale development of smart structures.

Simulation of the Superelastic Response of SMA Orthodontic Wires

1998 ◽  
Vol 120 (5) ◽  
pp. 676-685 ◽  
Author(s):  
D. Raboud
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Mechanical Response ◽  
Numerical Solutions ◽  
Initial Value ◽  
Orthodontic Wires ◽  
Wide Range ◽  
Superelastic Behavior ◽  
Low Modulus ◽  
Experimental Works

Shape-memory alloys have properties that make them well suited to a variety of applications. One application for which their unique combination of properties (large elastic range, low modulus of elasticity, ability to deliver nearly constant forces over a wide range of deformations) seems ideally suited is for orthodontic retraction appliances where these properties are very desirable. The mechanical response of shape-memory alloys is modeled by a simple constitutive model that captures the essential superelastic behavior of the shape-memory wires. An initial value approach that iteratively converges to the appropriate boundary conditions is utilized to deliver numerical solutions. Qualitative agreement is shown with previous experimental works. The possible benefits of using such wires in an orthodontic retraction appliance are then investigated.

Preliminary Experimental Study of the Effect of Shape Setting on Knitted SMA Structures

2017 ◽  
Author(s):  
Shiping Yi ◽  
Charles Weinberg ◽  
Kevin Eschen ◽  
Julianna Abel
Keyword(s):  
Medical Devices ◽  
Smart Materials ◽  
Applied Load ◽  
Mechanical Performance ◽  
Minimal Change ◽  
Constant Force ◽  
Wearable Technologies ◽  
Wide Range ◽  
Knitted Structure ◽  
The Impact

Smart materials can be integrated into textile structures to produce active textiles with tailored mechanical properties and large, complex actuation motions. Active textiles have the potential to enable a wide range of applications including wearable technologies, soft robots, medical devices, and aerospace structures. One type of active textile is the shape memory alloy (SMA) knitted structure. SMA knitted structures produce a range of kinematic actuation motions as a result of the bending, torsion, extension, and buckling of the SMA wire during the loop-based knitting manufacturing process. The kinematic motions of several different patterns of SMA knitted actuators have been cataloged, and the mechanical performance of basic knitted patterns have been characterized. However, the effect of shape-setting of knitted SMA structures has not been explored. This paper investigates the effect of post-manufacturing shape-setting on the kinematic and kinetic performance of basic SMA knitted structures. A design of experiment methodology was employed to isolate the impact of knitted pattern, SMA wire diameter, and shape-set curvature on mechanical performance. The introduction of a large curvature shape-set in the SMA wire resulted in a very stiff textile structure with a minimal change in length between the austenite and martensite states, thus, minimal capacity for large actuation deformations. Meanwhile, the introduction of a small curvature in the SMA wire resulted in a nearly constant force plateau and a larger change in length between the austenite and martensite state for the same applied load, and the potential for enhanced structural actuation deformations. Shape-setting is an additional design parameter that can be employed to enhance and tune the mechanical performance of knitted SMA structures.

Mechanical Bottom-up Nano-Assembling and Nano-Manipulation Using Shape Memory Alloy Nano-Gripper

2021 ◽  
Vol 323 ◽  
pp. 130-139
Author(s):  
Svetlana von Gratowski ◽  
Victor Koledov ◽  
Zoya Kosakowskiya ◽  
Peter Lega ◽  
Andrey Orlov ◽  
...  
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Field Effect Transistors ◽  
Building Blocks ◽  
Proof Of Concept ◽  
Bottom Up ◽  
Hierarchical Assembly ◽  
The Past ◽  
Wide Range ◽  
The World

The numerous 1-D and 2-D nanomaterials: nanotubes, nanowires (NWs), graphene, etc. were discovered, synthesized and intensively studied in the past decades. These nanomaterials had appeared to reveal the unique physical and functional properties allowing constructing the large number of nanodevice based on single nanoobjects. Recently many studies have led to a wide range of proof-of-concept of individual nanoscale devices including nanolasers, nanosensors, field-effect transistors (nanoFETs) and many others based on NWs, carbon nanotubes (CNT) and many other nanoobjects. Such nanodevices represent attractive building blocks for hierarchical assembly of microscale and macroscopic devices which are attractive for creating of micro-and –macro-devices and arrays by the bottom-up and hybrid paradigm. In this paper the conceptual survey is given of nowadays achievements in the field of mechanical bottom-up nanoassembling. We emphasize on the system based on smallest and the fastest in the World nanotweezer developed on the base of the new smart materials with shape memory effect for nanomanipulation of real nanoobjects. We discuss the recent experiments on nanomanipulation, nanoassembling and nanomanufacturing of nanoand micro-devices using this method, which in many cases can replaced very expensive “top-down” technologies.

scholarly journals Neutron Scattering as a Powerful Tool to Investigate Magnetic Shape Memory Alloys: A Review

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 829
Author(s):  
Natalia A. Río-López ◽  
Patricia Lázpita ◽  
Daniel Salazar ◽  
Viktor I. Petrenko ◽  
Fernando Plazaola ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Shape Memory Alloys ◽  
Neutron Scattering ◽  
Shape Memory ◽  
Smart Materials ◽  
Inelastic Neutron Scattering ◽  
Magnetic Shape Memory ◽  
Magnetic Shape Memory Alloys ◽  
Elastic Neutron ◽  
Wide Range

Magnetic shape memory alloys (MSMAs) are an interesting class of smart materials characterized by undergoing macroscopic deformations upon the application of a pertinent stimulus: temperature, stress and/or external magnetic fields. Since the deformation is rapid and contactless, these materials are being extensively investigated for a plethora of applications, such as sensors and actuators for the medical, automotive and space industries, energy harvesting and damping devices, among others. These materials also exhibit a giant magnetocaloric effect, whereby they are very promising for magnetic refrigeration. The applications in which they can be used are extremely dependent on the material properties, which are, in turn, greatly conditioned by the structure, atomic ordering and magnetism of a material. Particularly, exploring the material structure is essential in order to push forward the current application limitations of the MSMAs. Among the wide range of available characterization tools, neutron scattering techniques stand out in acquiring advanced knowledge about the structure and magnetism of these alloys. Throughout this manuscript, a comprehensive review about the characterization of MSMAs using neutron techniques is presented. Several elastic neutron scattering techniques will be explained and exemplified, covering neutron imaging techniques—such as radiography, tomography and texture diffractometry; diffraction techniques—magnetic (polarized neutron) diffraction, powder neutron diffraction and single crystal neutron diffraction, reflectometry and small angle neutron scattering. This will be complemented with a few examples where inelastic neutron scattering has been employed to obtain information about the phonon dispersion in MSMAs.

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