Download or read book Vibration Analysis of Carbon Nanotubes Using Continuum Model and Finite Element Model written by Hari Subramaniam and published by . This book was released on 2005 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of the thesis is to propose the methods of determining vibration behavior of carbon nanotubes (CNTs) using continuum models and finite element models. Secondary objective is to find the effect of van der Waals force on vibration of multiwalled carbon nanotubes . The study of vibration behavior of CNTs is important because of their potential engineering applications such as nano-mechanical resonators and tips of scanning probe instruments where they are subjected to mechanical vibrations. Continuum modeling is based on an elastic beam model. The interlayer van der Waals interactions are represented by Lennard- Jones potential. In finite element modeling, single walled nanotubes (SWNTs) are modeled as finite beam elements and multi-walled nanotubes (MWNTs) as finite solid elements. The interlayer van der Waals interactions are simulated by distributed springs. The proposed finite element approach and continuum approach for vibration analysis of CNTs are verified by comparing the results with experimental and analytical results available in the literature. The results from both continuum and finite element modeling show that the effect of van der Waals force on vibration of MWNTs are high for smaller aspect ratios irrespective of boundary conditions and number of layers; fixed nanotube than cantilever nanotube for the same dimensions ; five-walled nanotube than a double walled nanotube for the same aspect ratio.
Download or read book Modeling of Carbon Nanotubes Graphene and their Composites written by Konstantinos I. Tserpes and published by Springer Science & Business Media. This book was released on 2013-10-15 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large part of the research currently being conducted in the fields of materials science and engineering mechanics is devoted to carbon nanotubes and their applications. In this process, modeling is a very attractive investigation tool due to the difficulties in manufacturing and testing of nanomaterials. Continuum modeling offers significant advantages over atomistic modeling. Furthermore, the lack of accuracy in continuum methods can be overtaken by incorporating input data either from experiments or atomistic methods. This book reviews the recent progress in continuum modeling of carbon nanotubes and their composites. The advantages and disadvantages of continuum methods over atomistic methods are comprehensively discussed. Numerical models, mainly based on the finite element method, as well as analytical models are presented in a comparative way starting from the simulation of isolated pristine and defected nanotubes and proceeding to nanotube-based composites. The ability of continuum methods to bridge different scales is emphasized. Recommendations for future research are given by focusing on what still continuum methods have to learn from the nano-scale. The scope of the book is to provide current knowledge aiming to support researchers entering the scientific area of carbon nanotubes to choose the appropriate modeling tool for accomplishing their study and place their efforts to further improve continuum methods.
Download or read book Mechanical Behaviors of Carbon Nanotubes written by K.M. Liew and published by William Andrew. This book was released on 2016-12-25 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical Behaviors of Carbon Nanotubes: Theoretical and Numerical Approaches presents various theoretical and numerical studies on mechanical behaviors of carbon nanotubes. The main theoretical aspects included in the book contain classical molecular dynamics simulation, atomistic-continuum theory, atomic finite element method, continuum plate, nonlocal continuum plate, and shell models. Detailed coverage is also given to structural and elastic properties, trace of large deformation, buckling and post-buckling behaviors, fracture, vibration characteristics, wave propagation, and the most promising engineering applications. This book not only illustrates the theoretical and numerical methods for analyzing the mechanical behavior of carbon nanotubes, but also contains computational results from experiments that have already taken place. - Covers various theoretical and numerical studies, giving readers a greater understanding of the mechanical behavior of carbon nanotubes - Includes multiscale methods that provide the advantages of atomistic and continuum approaches, helping readers solve complex, large-system engineering problems - Allows engineers to create more efficient carbon nanotube structures and devices
Download or read book On Finite Element Vibration Analysis of Carbon Nanotubes written by Ishan Ali Khan and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this chapter, a finite element formulation is proposed to study the natural frequencies of double-walled carbon nanotubes modeled as, both, local and nonlocal Euler-Bernoulli beams, coupled with van der Waals interaction forces. The formulation uses Galerkin-weighted residual approach and employs Hermite cubic polynomial function to derive the linear eigenvalue problem. Natural frequencies are found for clamped-free, clamped-clamped and simply supported-simply supported boundary conditions. The results are in good agreement with the formulations found in the literature. The effect of nonlocal factor on the natural frequencies of the system is found out by comparing local and nonlocal results. Additionally, the universality of the proposed model is proven by application to a double-elastic Euler-Bernoulli beam. This formulation paves way for Finite Element Method (FEM) analysis of multi-walled CNTs-either locally or nonlocally.
Download or read book Advances in Vibration Analysis Research written by Farzad Ebrahimi and published by BoD – Books on Demand. This book was released on 2011-04-04 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibrations are extremely important in all areas of human activities, for all sciences, technologies and industrial applications. Sometimes these Vibrations are useful but other times they are undesirable. In any case, understanding and analysis of vibrations are crucial. This book reports on the state of the art research and development findings on this very broad matter through 22 original and innovative research studies exhibiting various investigation directions. The present book is a result of contributions of experts from international scientific community working in different aspects of vibration analysis. The text is addressed not only to researchers, but also to professional engineers, students and other experts in a variety of disciplines, both academic and industrial seeking to gain a better understanding of what has been done in the field recently, and what kind of open problems are in this area.
Download or read book Carbon Nanotube Reinforced Polymers written by Roham Rafiee and published by Elsevier. This book was released on 2017-10-06 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Carbon Nanotubes and Nanosensors written by Isaac Elishakoff and published by John Wiley & Sons. This book was released on 2013-03-04 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main properties that make carbon nanotubes (CNTs) a promising technology for many future applications are: extremely high strength, low mass density, linear elastic behavior, almost perfect geometrical structure, and nanometer scale structure. Also, CNTs can conduct electricity better than copper and transmit heat better than diamonds. Therefore, they are bound to find a wide, and possibly revolutionary use in all fields of engineering. The interest in CNTs and their potential use in a wide range of commercial applications; such as nanoelectronics, quantum wire interconnects, field emission devices, composites, chemical sensors, biosensors, detectors, etc.; have rapidly increased in the last two decades. However, the performance of any CNT-based nanostructure is dependent on the mechanical properties of constituent CNTs. Therefore, it is crucial to know the mechanical behavior of individual CNTs such as their vibration frequencies, buckling loads, and deformations under different loadings. This title is dedicated to the vibration, buckling and impact behavior of CNTs, along with theory for carbon nanosensors, like the Bubnov-Galerkin and the Petrov-Galerkin methods, the Bresse-Timoshenko and the Donnell shell theory.
Download or read book The NASTRAN Theoretical Manual written by and published by . This book was released on 1970 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Small scale Computational Vibration of Carbon Nanotubes Composite Structure written by Muzamal Hussain and published by CRC Press. This book was released on 2024-08-09 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents orthotropic vibration modeling and analysis of carbon nanotubes (CNTs) which be helpful in applications such as oscillators and in non-destructive testing, and also vibrations characteristics of armchair double-walled CNT by means of nonlocal elasticity shell model. The nonlocal shell model is established by inferring the nonlocal elasticity equations in to Kelvin’s theory, which is our particular motivation. The suggested method to investigate the solution of fundamental Eigen relations is wave propagation, which is a well-known and efficient technique to develop the fundamental frequency equations. The frequencies of three different types of SWCNTs are calculated. Also, the vibrations of the chiral single-walled carbon nanotube (SWCNTs) with non-local theory using wave propagation approach is investigated. It has been investigated that by increasing the nonlocal parameter decreases the frequencies and on increasing the aspect ratio increases the frequencies throughout the computation frequencies of clamped-free lower than that of clamped-clamped. Carbon nanotubes have a variety of applications because of their distinctive molecular structure and show unique electronic and mechanical properties because of their curvature. Nanotubes and micro-beams can be cited as one of the very applicable micro- and nano-structures in various systems, namely, sensing devices, communications and the quantum mechanics. The application of the tiny structures, specifically, carbon nanotubes in the sensors and actuators enforce the engineers to study vibrational properties of those structures experimentally and theoretically. In addition, they are utilized in different fields such as bioengineering, tissue engineering, computer engineering, optics, energy and environmental systems.
Download or read book Perusal of the Finite Element Method written by Radostina Petrova and published by BoD – Books on Demand. This book was released on 2016-12-14 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The finite element method (FEM) is a numerical technique for finding approximate solutions to different numerical problems. The practical applications of FEM are known as finite element analysis (FEA). FEA is a good choice for analyzing problems over complicated domains. The first three chapters of this book contribute to the development of new FE techniques by examining a few key hurdles of the FEM and proposing techniques to mitigate them. The next four chapters focus on the close connection between the development of a new technique and its implementation. Current state-of-the-art software packages for FEA allow the construction, refinement, and optimization of entire designs before manufacturing. This is convincingly demonstrated in the last three chapters of the book with examples from the field of biomechanical engineering. This book presents a current research by highlighting the vitality and potential of the finite elements for the future development of more efficient numerical techniques, new areas of application, and FEA's important role in practical engineering.
Download or read book Wave Propagation in Nanostructures written by Srinivasan Gopalakrishnan and published by Springer Science & Business Media. This book was released on 2013-09-10 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wave Propagation in Nanostructures describes the fundamental and advanced concepts of waves propagating in structures that have dimensions of the order of nanometers. The book is fundamentally based on non-local elasticity theory, which includes scale effects in the continuum model. The book predominantly addresses wave behavior in carbon nanotubes and Graphene structures, although the methods of analysis provided in this text are equally applicable to other nanostructures. The book takes the reader from the fundamentals of wave propagation in nanotubes to more advanced topics such as rotating nanotubes, coupled nanotubes, and nanotubes with magnetic field and surface effects. The first few chapters cover the basics of wave propagation, different modeling schemes for nanostructures and introduce non-local elasticity theories, which form the building blocks for understanding the material provided in later chapters. A number of interesting examples are provided to illustrate the important features of wave behavior in these low dimensional structures.
Download or read book Finite Element Modeling of Nanotube Structures written by Mokhtar Awang and published by Springer. This book was released on 2015-11-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a new approach to modeling carbon structures such as graphene and carbon nanotubes using finite element methods, and addresses the latest advances in numerical studies for these materials. Based on the available findings, the book develops an effective finite element approach for modeling the structure and the deformation of grapheme-based materials. Further, modeling processing for single-walled and multi-walled carbon nanotubes is demonstrated in detail.
Download or read book Static And Dynamic Problems Of Nanobeams And Nanoplates written by Snehashish Chakraverty and published by World Scientific. This book was released on 2016-10-14 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will deal with different sections associated with bending, buckling and vibration of nanobeams and nanoplates along with systematic description of handling the complexities when nanoscales are considered. The introduction includes basic ideas concerned with nanostructures, the algorithms and iterations followed in numerical methods and introduction to beam and plate theories in conjunction with nonlocal elasticity theory applied in nanostructures.Next, the investigation of nanobeams and nanoplates subjected to different sets of boundary conditions based on various nonlocal theories will be included. The varieties of physical and geometrical parameters that influence the bending, buckling and vibration mechanisms will be summarized.Finally, effect of environments such as thermal environment, Winkler-Pasternak elastic foundations and non-uniformity etc. on the buckling and vibration mechanisms will be illustrated.
Download or read book A Primer on the Geometry of Carbon Nanotubes and Their Modifications written by Sadegh Imani Yengejeh and published by Springer. This book was released on 2015-01-12 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents a comprehensive system for categorizing carbon nanotubes and their modifications in terms of nano sheets, nanotubes, microscopic and atomic modifications. In addition, the material and geometric properties of these nano-configurations are addressed. Lastly, it introduces a number of common software packages for geometry generation and several commercial finite element programs.
Download or read book Nonlocal Continuum Field Theories written by A. Cemal Eringen and published by Springer Science & Business Media. This book was released on 2007-06-14 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonlocal continuum field theories are concerned with material bodies whose behavior at any interior point depends on the state of all other points in the body -- rather than only on an effective field resulting from these points -- in addition to its own state and the state of some calculable external field. Nonlocal field theory extends classical field theory by describing the responses of points within the medium by functionals rather than functions (the "constitutive relations" of classical field theory). Such considerations are already well known in solid-state physics, where the nonlocal interactions between the atoms are prevalent in determining the properties of the material. The tools developed for crystalline materials, however, do not lend themselves to analyzing amorphous materials, or materials in which imperfections are a major part of the structure. Nonlocal continuum theories, by contrast, can describe these materials faithfully at scales down to the lattice parameter. This book presents a unified approach to field theories for elastic solids, viscous fluids, and heat-conducting electromagnetic solids and fluids that include nonlocal effects in both space and time (memory effects). The solutions to the field equations agree remarkably well with atomic theories and experimental observations.
Download or read book Equivalent continuum Modeling of Nano structured Materials written by Gregory M. Odegard and published by . This book was released on 2001 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method has been developed for modeling structure-property relationships of nano-structured materials. This method serves as a link between computational chemistry and solid mechanics by substituting discrete molecular structures with an equivalent-continuum model. It has been shown that this substitution may be accomplished by equating the vibrational potential energy of a nano-structured material with the strain energy of representative truss and continuum models. As an important example with direct application to the development and characterization of single-walled carbon nanotubes, the model has been applied to determine the effective continuum geometry of a graphene sheet. A representative volume element of the equivalent-continuum model has been developed with an effective thickness. This effective thickness has been shown to be similar to, but slightly smaller than, the interatomic spacing of graphite.
Download or read book Atomistic based Finite Element Simulation of Carbon Nanotubes written by Yang Yang and published by . This book was released on 2008 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since first found in the form of multi-walled carbon nanotubes (MWNTs) by Iijima (1991), carbon nanotube (CNT) for its outstanding and unique properties have gained overwhelming attentions from across the spectrum of the science and engineering fields. CNTs are structurally perfect, small size, low density, high stiffness, high strength (Qian et al., 2002), and their electronic properties depend on the particular distortion as well as the initial tube diameter and chirality, ranging from narrow-gap or moderate-gap semiconducting to metallic (Pantano et al., 2004b), which can be utilized in nanoscale sensors and devices. These appealing characteristics provide strong drives for the possible applications of CNTs as a novel material. However, a sufficient understanding of the mechanics of CNTs and the effects of mechanical deformations on the electrical properties still remains obscure. In this study we focus on CNTs' mechanical responses to externally applied loads by implementing a new atomistic formulation-based finite element method. The skeleton of this new diagram lies in two facts, firstly it uses the subdivision scheme which can render a high-order smooth limit surface so that Kirchoff-love thin shell formulae could be applied, secondly the Born rule for space-filling crystals is used to link between the atomistic and the continuum deformations.
