Download Free Multiscale Investigations On Structural Properties And Mechanical Application Of Carbon Nanotube Sheets Book in PDF and EPUB Free Download. You can read online Multiscale Investigations On Structural Properties And Mechanical Application Of Carbon Nanotube Sheets and write the review.

The recent emergence of new nano-materials and nanostructures brings up the development of nanotube sheets or the so-called buckypapers for a variety of meaningful applications in actuating and mechanical properties alterations for structural and electromechanical systems. However, the technology of fabrication as well as the understanding of nanomechanics behaviors for nanotube sheets is still in its infancy. This motivates the present research aimed at investigating the mechanical strength properties and potential applications of buckypapers by using finite element methods, atomic scale modeling and simulation, and experimental tests. In the first part of the research, experiment-purpose buckypapers have been fabricated in house to investigate their contributions to the strengths of other macrostructures to which they are integrated. Toward this end, a finite element procedure has been developed for three-dimensional modeling of multilayered nanostructures having embedded buckypapers and the resulted natural frequencies increment due to the high stiffness of buckypapers are agreeably verified by experimental tests. In addition, the experimental testing results further imply that buckypapers have superior damping properties indicated by the clear reductions of the power spectral density readings affected by the buckypaper dampers. This first time investigated and verified profound damping characteristics of buckypapers may be useful for vibration suppression, acoustic noise reduction, and structural enhancement for materials and structures where add-on weight is a concern such as sports equipments and airframes. This theoretical and experimental finding of buckypapers' superior damping property is deemed to be the first major contribution of the dissertation research. To delve into the mechanical properties of carbon nanotubes and buckypapers, in the second part of the dissertation, the atomic scale models of carbon nanotubes and buckypapers are created for the investigation. Along this line, novel simulation models for single and multilayer buckypapers were built which enabled us to understand the bending stiffness and other mechanical properties of buckypapers through an atomic scaled analysis against the existing empirical methods. This new approach of analyzing and observing buckypaper's properties is the second contribution of this dissertation. The results from the simulation gave a reasonably expected Young's moduli for single wall carbon nanotubes comparing to those found in the literature; for single layer and multilayer buckypapers model, higher Young's moduli values obtained in the simulations than previous done experimental testings which are considered mainly due to the exclusion of such factors as particles impurity, uneven thickness, imperfect alignments, etc. Therefore, these higher values may represent the optimal goal of Young's moduli for buckypapers which could be achieved ultimately when their fabrication techniques are continuously improved in the future.
This book provides a broad overview on the relationship between structure and mechanical properties of carbon nanomaterials from world-leading scientists in the field. The main aim is to get an in-depth understanding of the broad range of mechanical properties of carbon materials based on their unique nanostructure and on defects of several types and at different length scales. Besides experimental work mainly based on the use of (in-situ) Raman and X-ray scattering and on nanoindentation, the book also covers some aspects of multiscale modeling of the mechanics of carbon nanomaterials.
After a short introduction and a brief review of the relation between carbon nanotubes, graphite and other forms of carbon, the synthesis techniques and growth mechanisms for carbon nanotubes are described. This is followed by reviews on nanotube electronic structure, electrical, optical, and mechanical properties, nanotube imaging and spectroscopy, and nanotube applications.
This discovery of carbon nanotubes (CNT) three decades ago ushered in the technological era of nanotechnology. Among the most widely studied areas of CNT research is their use as structural reinforcements in composites. This book describes the development of CNT reinforced metal matrix composites (CNT-MMCs) over the last two decades. The field of CNT-MMCs is abundant in fundamental science, rich in engineering challenges and innovations and ripe for technological maturation and commercialization. The authors have sought to present the current state of the-art in CNT-MMC technology from their synthesis to their myriad potential end-use applications. Specifically, topics explored include: • Advantages, limitations, and evolution of processing techniques used to synthesize and fabricate CNT-MMCs • Emphasizes dispersion techniques of CNTs in metallic systems, a key challenge to the successful and widespread implementation of CNT-MMCs. Methods for quantification and improved control of CNT distributions are presented • Methods for quantification and improved control of CNT distributions are presented • Characterization techniques uniquely suited for charactering these nanoscale materials and their many chemical and physical interactions with the metal matrix, including real-time in-situ characterization of deformation mechanisms • Electron microscope images from premier studies enrich discussions on micro-mechanical modeling, interfacial design, mechanical behavior, and functional properties • A chapter is dedicated to the emergence of dual reinforcement composites that seek to enhance the efficacy of CNTs and lead to material properties by design This book highlights seminal findings in CNT-MMC research and includes several tables listing processing methods, associated CNT states, and resulting properties in order to aid the next generation of researchers in advancing the science and engineering of CNT-MMCs. In addition, a survey of the patent literature is presented in order to shed light on what the first wave of CNT-MMC commercialization may look like and the challenges that will have to be overcome, both technologically and commercially.
Carbon Nanotube-Reinforced Polymers: From Nanoscale to Macroscale addresses the advances in nanotechnology that have led to the development of a new class of composite materials known as CNT-reinforced polymers. The low density and high aspect ratio, together with their exceptional mechanical, electrical and thermal properties, render carbon nanotubes as a good reinforcing agent for composites. In addition, these simulation and modeling techniques play a significant role in characterizing their properties and understanding their mechanical behavior, and are thus discussed and demonstrated in this comprehensive book that presents the state-of-the-art research in the field of modeling, characterization and processing. The book separates the theoretical studies on the mechanical properties of CNTs and their composites into atomistic modeling and continuum mechanics-based approaches, including both analytical and numerical ones, along with multi-scale modeling techniques. Different efforts have been done in this field to address the mechanical behavior of isolated CNTs and their composites by numerous researchers, signaling that this area of study is ongoing. - Explains modeling approaches to carbon nanotubes, together with their application, strengths and limitations - Outlines the properties of different carbon nanotube-based composites, exploring how they are used in the mechanical and structural components - Analyzes the behavior of carbon nanotube-based composites in different conditions
Carbon nanotubes are macromolecules of carbon in a periodic hexagonal arrangement with a cylindrical shell shape. Carbon nanotubes have been subjected to extensive research, with subsequent predictions of extremely high strength and exceptional electronic and thermal properties. They also hold substantial promise as fibers in composites and other devices for the development of superconductive devices for micro-electro-mechanical and nano-electro-mechanical system applications. It is expected that the material has great potential in biological, medical, energy storage, sensor, and other applications. It has been broadly recognized that atomic modeling of carbon nanotube is a powerful tool for analysis of carbon nanotube. Due to massive computations involved, the atomic modeling is limited to systems with a small number of molecules and atoms. On the other hand, attempts at applying continuum mechanics models to better investigate the analysis of carbon nanotube with large sizes have been initiated. However, continuum models are unable to adequately capture the atomic structures of carbon nanotube, and the applicability of the models needs to be justified. Recently, developments of multiscale methods have been proposed to the analysis of carbon nanotube. This book is dedicated to the publication of recent developments in modeling of carbon nanotube via atomic modeling, continuum modeling and multiscale methods for predictions of mechanical, electronic, and thermal properties of carbon nanotube. A wide range of fundamentally theoretical, computational topics on modeling and applications of carbon nanotube will be covered in the book. In addition, applications of carbon nanotubes as nano-devices in atomic and molecular transportations and bistable devices in switching or memory elements in signal processing and communications are also reported. It is with great pleasure that we present this book that covers a very wide and varied range of subject areas in modeling and applications of carbon nanotubes. The first chapter employs molecular dynamics simulations to show macroscopic flows of atomic and molecular hydrogen, helium, and a mixture of both gases both inside and outside a carbon nanotube. In particular, the simulations show a nanoseparation effect of the two gases. The new results in the chapter show the mass selectivity of the nanopumping effect can be used to develop a highly selective filter for various gases. The second chapter introduces a fine continuum model that is developed by virtue of the higher-order continuum theory. Moreover, a mesh-free computational framework is developed to implement the numerical simulation of single- walled carbon nanotubes. The rationality of the higher-order continuum model and the efficiency of mesh-free method are illustrated and discussed in the chapter. The study on the mechanics of buckled single-walled and multiwalled carbon nanotubes, carbon nanotube bundles and coupling effect between adjacent carbon nanotubes is reported in chapter three. Simple expressions of the buckle wavelength, amplitude and critical strain for buckling are given analytically, which show good agreement with experiments. Chapter 4 investigate the applicability of elastic shell model in analysis of graphene and carbon nanotubes. The author reports that the elasticity of graphene should be modeled as a shell composed of 2-dimensional (2D) isotropic materials with proper parameters rather than conventional 3D materials based on calculations by density functional theory. In addition, the elasticity of single-walled carbon nanotube with relative large radius can also be modeled as a shell composed of 2D isotropic materials, whereas the elasticity of single-walled carbon nanotubes with relative small radius should be modeled as a more complicated shell with seven elastic constants rather than the orthotropic thin shell. Mechanical integrity of carbon nanotubes is summarized in chapter 5. Young s modulus for the resistance to the infinitesimal deformation and ultimate strength to the finite deformation are tabled, which have been obtained by experiments, molecular dynamics simulations, and ab-initio calculations. Also the recent continuous modeling of carbon nanotubes is sorted out in tracing its advancement in the chapter. Chapter 6 presents an overview of studies on the wave propagation and the vibrational properties in carbon nanotubes by computational modeling and simulation. The models include the atomic-based continuum model, the Euler-beam model, the Timoshenko beam model, and the three-dimensional elastic shell model. Chapter seven reports the investigations of torsional buckling of both single-walled and double-walled carbon nanotubes. In the study of doubled-walled carbon nanotubes via molecular dynamics, a newly revealed buckling mode with one or three thin local rims on the outer tube is discovered while the inner tube shows a helically aligned buckling mode in three dimensions. The distinct buckling modes of the two tubes imply the inapplicability of continuum mechanics modeling in which it is postulated that the buckling modes of the constituent tubes have the same shape. The mechanical properties of single walled carbon nanotubes under both tensile and torsion are investigated using classical molecular dynamics simulations in chapter 8, based on reactive empirical bond-order potential. Based on the predicted mechanical properties, it is predicted that nanotubes may represent new candidates for novel porous, flexible and high strength and tough materials, e.g. ideal as scaffolds in the regenerative medicine. Bistable devices have been widely used as switching or memory elements in signal processing and communications. The bistablity is generally realized electrically or optically. Due to their small size and unique mechanical properties, carbon nanotubes have been proposed to form bistable devices mechanically. The chapter 9 reviews the recent advances of mechanical bistable devices of carbon nanotubes. In the final chapter, the authors have discussed a theoretical model based on kinetic concept of fracture of solids and molecular mechanics simulations for studying the time-dependent behavior of single-walled carbon nanotubes. The major advantage of this model is that the problem of real-time molecular level simulation is circumvented. Compared with recently published data on creep rupture of SWCNT ropes, it is seen that the predictions by the present model is quite reasonable, thus setting up a framework for modeling the time-dependent behavior of carbon nanotubes and their composites. We would like to extend our sincere thanks to the authors for their contributions, especially their precious time and efforts invested in the book. We also would like to thank Transworld Research Network Publishers for the opportunity to publish the book to address very important and challenging issues. The support and love from our families are deeply appreciated.
Carbon nanotubes are rolled up graphene sheets with a quasi-one-dimensional structure of nanometer-scale diameter. In these last twenty years, carbon nanotubes have attracted much attention from physicists, chemists, material scientists, and electronic device engineers, because of their excellent structural, electronic, optical, chemical and mechanical properties. More recently, demand for innovative industrial applications of carbon nanotubes is increasing. This book covers recent research topics regarding syntheses techniques of carbon nanotubes and nanotube-based composites, and their applications. The chapters in this book will be helpful to many students, engineers and researchers working in the field of carbon nanotubes.
Carbon nanotubes are rolled up graphene sheets with a quasi-one-dimensional structure of nanometer-scale diameter. In these last twenty years, carbon nanotubes have attracted much attention from physicists, chemists, material scientists, and electronic device engineers because of their excellent structural, electronic, optical, chemical and mechanical properties. Carbon nanotube research, especially that aiming at industrial applications, is becoming more important. This book covers recent research topics regarding the physical, structural, chemical and electric properties on carbon nanotubes. All chapters were written by researchers who are active on the front lines. The chapters in this book will be helpful to many students, engineers and researchers working in the field of carbon nanotubes.
This volume presents the characterization methods involved with carbon nanotubes and carbon nanotube-based composites, with a more detailed look at computational mechanics approaches, namely the finite element method. Special emphasis is placed on studies that consider the extent to which imperfections in the structure of the nanomaterials affect their mechanical properties. These defects may include random distribution of fibers in the composite structure, as well as atom vacancies, perturbation and doping in the structure of individual carbon nanotubes.
Fibre reinforced polymer (FRP) composites are used in almost every type of advanced engineering structure, with their usage ranging from aircraft, helicopters and spacecraft through to boats, ships and offshore platforms and to automobiles, sports goods, chemical processing equipment and civil infrastructure such as bridges and buildlings. The usage of FRP composites continues to grow at an impessive rate as these materials are used more in their existing markets and become established in relatively new markets such as biomedical devices and civil structures. A key factor driving the increased applications of composites over the recent years is the development of new advanced forms of FRP materials. This includes developments in high performance resin systems and new styles of reinforcement, such as carbon nanotubes and nanoparticles. This book provides an up-to-date account of the fabrication, mechanical properties, delamination resistance, impact tolerance and applications of 3D FRP composites. The book focuses on 3D composites made using the textile technologies of weaving, braiding, knitting and stiching as well as by z-pinning.