Download or read book Thermomechanical Modeling of Shape Memory Alloy based Microactuators written by Marian Hörsting and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermomechanical Modeling and Analysis of Flexible Structures with Shape Memory Alloy Actuators written by Steven Gongming Shu and published by . This book was released on 1996 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shape Memory Microactuators written by Manfred Kohl and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overview of recent achievements, describing the microactuator development of microvalves and liner actuators comprehensively from concept through prototype. Further key aspects included are three-dimensional models for handling complex SMA actuator geometries and coupled simulation routines that take multifunctional properties into account. Mechanical and thermal optimization criteria are introduced for actuator design, allowing an optimum use of the shape memory effect. It is shown that some of the prototypes presented, e.g. SMA microgrippers, already outperform conventional components.

Download or read book Shape Memory Alloy Actuators written by Mohammad H. Elahinia and published by John Wiley & Sons. This book was released on 2016-01-19 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a systematic approach to realizing NiTi shape memory alloy actuation, and is aimed at science and engineering students who would like to develop a better understanding of the behaviors of SMAs, and learn to design, simulate, control, and fabricate these actuators in a systematic approach. Several innovative biomedical applications of SMAs are discussed. These include orthopedic, rehabilitation, assistive, cardiovascular, and surgery devices and tools. To this end unique actuation mechanisms are discussed. These include antagonistic bi-stable shape memory-superelastic actuation, shape memory spring actuation, and multi axial tension-torsion actuation. These actuation mechanisms open new possibilities for creating adaptive structures and biomedical devices by using SMAs.

Download or read book Thermomechanical Modeling and Experimentation for SMA Actuators Under Cyclic Loading written by and published by . This book was released on 2002 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimentally validated thermomechanical actuation model for shape memory alloy (SMA) actuators undergoing non proportional cyclic loading, fully coupled with the evolution of plastic strains is developed. The model is numerically implemented in a form suitable for finite element analysis. Material characterization of SMA actuators is also performed in this research effort. Emphasis is given on the effect of plastic strains on the properties of SMA actuators. The data collected during the characterization is utilized to calibrate the thermomechanical SMA model. After the model is calibrated, different loading cases are investigated, including non-proportional loading paths. Finally, the fatigue life of SMA actuators is also investigated. A test frame for fatigue experiments is developed and numerous fatigue tests are performed.

Download or read book Linear Shape Memory Alloy Thermomechanical Actuators written by Velaphi Msomi and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The thermally activated changes in crystal structure in nickel-titanium shape memory alloy (SMA) material, which produces transformation strains of an order of magnitude higher than and opposite to the thermal strains, have been described using different models. Some of these models are defined by cyclic functions (trigonometric functions) which they become complex to control when they are subjected to a wide range of transformation temperatures. This chapter presents an alternative model to better describe the behavior of SMA for a more general temperature range, which an SMA-powered actuator might be subjected to. The proposed model is then implemented to the analysis of one-dimensional (1D) problem oriented to the two-dimensional (2D) space. The simulation results were then graphically compared to the experiment.

Download or read book Thermal Modeling of Shape Memory Alloy Wire Actuators for Automotive Applications written by Huilong Ma and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermomechanical Training and Characterization of Shape Memory Alloy Axial Actuators written by Marcus Patrick Becker and published by . This book was released on 2010 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although considerable work has been performed to understand the key mechanisms of Shape Memory Alloy (SMA) behavior, little of this work follows a standard testing protocol, quantifies a conditioning methodology, or develops data appropriate for design of SMA actuators. One major issue that limits the ability of the material from being used directly as an actuator is the large, non-recoverable strains likely to accrue in the material during each training cycle, mechanical or thermal. When mechanical or thermal cycling is performed, a hysteresis curve develops and reaches a steady state strain recovery response. At the point where permanent plastic strain stops growing, or saturates, the SMA has been successfully trained. The focus of this work is oriented toward SMAs in general, but all testing and experimentation was carried out on Nickel-Titanium (NiTi) alloys. The experimentation and testing was performed on a combination of 4 different sizes and 3 different NiTi alloy compositions. Thermomechanical testing was performed to determine critical values to describe the stress-temperature phase space of the materials and parameters to model the applied stress and transformation strain relationship. All material size and alloy combinations were tested in the as-received, or as-machined, and fully annealed state. The results of the training and actuation strain characterization process developed in this work shows that the samples that experienced Transformation Induced Plasticity (TRIP), greater than 2% during the training process and exhibit Two-Way Shape Memory (TWSM) after being fully trained, share a very similar applied stress versus transformation strain curve. This curve is modeled by the Back Stress formulation derived from the Gibbs Free Energy constitutive model by Bo & Lagoudas. The design space created by the Back Stress formulation, recrystallization temperature, and training stress allows SMA materials to be characterized and implemented as stable 1-D actuators. This research formalized a thermomechanical training and characterization method for uniaxial SMA actuators by addressing the interaction between processing, recoverable and non-recoverable deformation. Using various sizes and NiTi alloy combinations, this research develops and evaluates a method to train and characterize a diverse range of SMAs through a set of thermomechanical and physical property measurements.

Download or read book Microactuators written by Massood Tabib-Azar and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: 219 8. 2 Sensors 221 8. 3 Physical Sensors 222 8. 3. 1 Electrical Sensing Means 223 8. 3. 2 Magnetic Field Methods 231 8. 3. 3 Optical Methods 232 8. 4 Chemical Sensors 241 8. 4. 1 Electrical Gas and Chemical Sensors 243 8. 4. 2 Guided-Optics Intrinsic Chemical Sensors 246 8. 4. 3 Extrinsic Chemical Sensors 250 8. 4. 4 Polymer Waveguide Chemical Sensors 251 8. 4. 5 Surface Plasmon Chemical Sensors 252 8. 4. 6 Indicator-Mediated Extrinsic Sensing 253 8. 4. 7 Optical Biosensors 256 8. 4. 8 Ultrasonic Gas and Chemical Sensors 257 8. 4. 9 Intelligent Sensors 258 8. 5 Connections/Links and Wiring 258 8. 5. 1 Optical Links 260 8. 5. 2 Requirement on the Processing Unit/Intelligence 262 8. 6 Actuators 263 8. 7 Signal Processing/Computing 264 8. 7. 1 Implicit Computation 266 8. 7. 2 Explicit Computation 267 8. 8 References 274 Subject Index 279 Micro-Actuators (Electrical, Magnetic, Thermal, Optical, Mechanical, and Chemical) It has become quite apparent that sensors and actuators are the main bottleneck of the modem information processing and control systems. Microprocessors and computers used to be the main limiting element in most information processing systems. But thanks to the enonnous progress in the microelectronics industry, most information analysis tasks can be processed in real time. The data has to be acquired by the processor in some form and processed and used to produce some useful function in the real world.

Download or read book Thermomechanical Behavior of High temperature Shape Memory Alloy Ni Ti Pd Pt Actuators written by Douglas E. Nicholson and published by . This book was released on 2011 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: To date the commercial use of shape memory alloys (SMAs) has been mostly limited to binary NiTi alloys with transformation temperatures approximately in the -100 to 100°C range. In an ongoing effort to develop high-temperature shape memory alloys (HTSMAs), ternary and quaternary additions are being made to binary NiTi to form NiTi-X (e.g., X: Pd, Pt, Au and Hf) alloys. Stability and repeatability can be further increased at these higher temperatures by limiting the stress, but the tradeoff is reduced work output and stroke. However, HTSMAs operating at decreased stresses can still be used effectively in actuator applications that require large strokes when used in the form of springs. The overall objective of this work is to facilitate the development of HTSMAs for use as high-force actuators in active/adaptive aerospace structures. A modular test setup was assembled with the objective of acquiring stroke, stress, temperature and moment data in real time during joule heating and forced convective cooling of Ni19.5Ti50.5Pd25Pt5 HTSMA springs. The spring actuators were evaluated under both monotonic axial loading and thermomechanical cycling. The role of rotational constraints (i.e., by restricting rotation or allowing for free rotation at the ends of the springs) on stroke performance was also assessed. Recognizing that evolution in the material microstructure results in changes in geometry and vice versa in HTSMA springs, the objective of the present study also included assessing the contributions from the material microstructural evolution, by eliminating contributions from changes in geometry, to overall HTSMA spring performance. The finite element method (FEM) was used to support the analytical analyses and provided further insight into the behavior and heterogeneous stress states that exist in these spring actuators. Furthermore, with the goal of improving dimensional stability there is a need to better understand the microstructural evolution in HTSMAs that contributes to irrecoverable strains. Towards this goal, available Ni29.5Ti50.5Pd20 neutron diffraction data (from a comparable HTMSA alloy without the solid solution strengthening offered by the Pt addition) were analyzed. The data was obtained from in situ neutron diffraction experiments performed on Ni29.5Ti50.5Pd20 during compressive loading while heating/cooling, using the Spectrometer for Materials Research at Temperature and Stress (SMARTS) at Los Alamos National Laboratory. Specifically, in this work emphasis was placed on neutron diffraction data analysis via Rietveld refinement and capturing the texture evolution through inverse pole figures. Such analyses provided quantitative information on the evolution of lattice strain, phase volume fraction (including retained martensite that exists above the austenite finish temperature) and texture (martensite variant reorientation and detwinning) under temperature and stress. Financial support for this work from NASA's Fundamental Aeronautics Program Supersonics Project (NNX08AB51A), Subsonic Fixed Wing Program (NNX11AI57A) and the Florida Center for Advanced Aero-Propulsion (FCAAP) is gratefully acknowledged. It benefited additionally from the use of the Lujan Neutron Scattering Center at Los Alamos National Laboratory, which is funded by the Office of Basic Energy Sciences (Department of Energy) and is operated by Los Alamos National Security LLC under DOE Contract DE-AC52-06NA25396.

Download or read book Development of Microactuators Based on the Magnetic Shape Memory Effect written by Yeduru, Srinivasa Reddy and published by KIT Scientific Publishing. This book was released on 2013-12-10 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: The giant magneto-strain effect in Ni-Mn-Ga alloys is particularly attractive for actuator applications. Two different approaches are being pursued to develop MSM microactuators. To observe large deflections of Ni-Mn-Ga microactuators, the material should be exhibiting low twinning stress and large magnetic anisotropy. In addition, design rules and boundary conditions for operating the Ni-Mn-Ga actuator material are having significant importance for evolution of performance characteristics.

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1992 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of a Numerical Model for High Temperature Shape Memory Alloys written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-07 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thermomechanical hysteresis model for a high-temperature shape memory alloy (HTSMA) actuator material is presented. The model is capable of predicting strain output of a tensile-loaded HTSMA when excited by arbitrary temperature-stress inputs for the purpose of actuator and controls design. Common quasi-static generalized Preisach hysteresis models available in the literature require large sets of experimental data for model identification at a particular operating point, and substantially more data for multiple operating points. The novel algorithm introduced here proposes an alternate approach to Preisach methods that is better suited for research-stage alloys, such as recently-developed HTSMAs, for which a complete database is not yet available. A detailed description of the minor loop hysteresis model is presented in this paper, as well as a methodology for determination of model parameters. The model is then qualitatively evaluated with respect to well-established Preisach properties and against a set of low-temperature cycled loading data using a modified form of the one-dimensional Brinson constitutive equation. The computationally efficient algorithm demonstrates adherence to Preisach properties and excellent agreement to the validation data set.

Download or read book Meso to Micro Actuators written by Alberto Borboni and published by CRC Press. This book was released on 2008-05-05 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring the design and use of micro- and meso-actuators, this book begins with theory and a general synopsis of the state-of-the-art in theoretical research. It discusses how to employ modern approaches in research and design activity, then presents a systematic list of already available products and details their potential for use. Design possibilities based on new technologies are clearly separated from those due to scale reduction, aiding in the selection of proper technology. The author takes a multi-physic approach to guarantee a comprehensive modeling technique, while the many references to experimental data and to existing microacutators assure an effective applicability of proposed theories.

Download or read book Thin Film Shape Memory Alloys written by Shuichi Miyazaki and published by Cambridge University Press. This book was released on 2009-09-03 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first dedicated book describing the properties, preparation, characterization and device applications of TiNi-based shape memory alloys.

Download or read book Shape Memory Composites Based on Polymers and Metals for 4D Printing written by Muni Raj Maurya and published by Springer Nature. This book was released on 2022-05-18 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape Memory Composites Based on Polymers and Metals for 4D Printing is a thorough discussion of the physics and chemistry behind this developing area of materials science. It provides readers with a clear exposition of shape-memory-composite (SMC) preparation techniques for 3D and 4D printing processes and explains how intelligent manufacturing technology may be applied in fields such as robotics, construction, medical science, and smart sensors. The book covers fundamental background knowledge on the synthesis of shape memory polymers (SMPs) and shape memory alloys (SMAs), and additive manufacturing techniques. Polymers and metals and their roles in 4D printing are dealt with separately, and applications of 4D printing are treated in their own chapter. The different alloy compositions and nanoparticle fillers in polymer composites are examined in detail, along with the key mechanisms involved in their processing. Hybrid nanofillers and synergistic composite mixtures, which are either in extensive current use or have shown promising outcomes in the field of 4D printing, are thoroughly discussed. Differences between these novel SMCs and traditional metal alloys, organic and inorganic composites are presented, and means by which they can improve mechanical properties that are triggered by external sources like magnetic field, temperature, and pH of solvent, are set out. This book provides practitioners, industrial researchers, and scholars with a state-of-the-art overview of SMP/SMA synthesis, additive manufacturing, modification in synthesis of SMCs for 4D printing, and their likely future applications.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt: