Equivalent-continuum Modeling of Nano-structured Materials

Equivalent-continuum Modeling of Nano-structured Materials PDF Author: Gregory M. Odegard
Publisher:
ISBN:
Category : Nanostructured materials
Languages : en
Pages : 38

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Book Description
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.

Equivalent-continuum Modeling of Nano-structured Materials

Equivalent-continuum Modeling of Nano-structured Materials PDF Author: Gregory M. Odegard
Publisher:
ISBN:
Category : Nanostructured materials
Languages : en
Pages : 38

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Book Description
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.

Equivalent-Continuum Modeling With Application to Carbon Nanotubes

Equivalent-Continuum Modeling With Application to Carbon Nanotubes PDF Author:
Publisher:
ISBN:
Category : Continuum mechanics
Languages : en
Pages : 32

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Book Description
A method has been proposed for developing 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 equivalent-continuum models. 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 important examples with direct application to the development and characterization of single-walled carbon nanotubes and the design of nanotube-based devices, the modeling technique has been applied to determine the effective-continuum geometry and bending rigidity of a graphene sheet, A representative volume element of the chemical structure of graphene has been substituted with equivalent-truss and equivalent-continuum models. As a result, an effective thickness of the continuum model has been determined.

Equivalent-Continuum Modeling with Application to Carbon Nanotubes

Equivalent-Continuum Modeling with Application to Carbon Nanotubes PDF Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781723723605
Category : Science
Languages : en
Pages : 32

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Book Description
A method has been proposed for developing 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 equivalent-continuum models. 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 important examples with direct application to the development and characterization of single-walled carbon nanotubes and the design of nanotube-based devices, the modeling technique has been applied to determine the effective-continuum geometry and bending rigidity of a graphene sheet. A representative volume element of the chemical structure of graphene has been substituted with equivalent-truss and equivalent continuum models. As a result, an effective thickness of the continuum model has been determined. This effective thickness has been shown to be significantly larger than the interatomic spacing of graphite. The effective thickness has been shown to be significantly larger than the inter-planar spacing of graphite. The effective bending rigidity of the equivalent-continuum model of a graphene sheet was determined by equating the vibrational potential energy of the molecular model of a graphene sheet subjected to cylindrical bending with the strain energy of an equivalent continuum plate subjected to cylindrical bending.Odegard, Gregory M. and Gates, Thomas S. and Nicholson, Lee M. and Wise, Kristopher E.Langley Research CenterCARBON NANOTUBES; CONTINUUM MODELING; SOLID MECHANICS; NANOTECHNOLOGY; GRAPHITE; POTENTIAL ENERGY; TRUSSES; VIBRATION; BENDING

Computational Materials: Modeling and Simulation of Nanostructured Materials and Systems

Computational Materials: Modeling and Simulation of Nanostructured Materials and Systems PDF Author: Thomas S. Gates
Publisher:
ISBN:
Category : Composite materials
Languages : en
Pages : 24

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Book Description


Constitutive Modeling of Nanotube-reinforced Polymer Composite Systems

Constitutive Modeling of Nanotube-reinforced Polymer Composite Systems PDF Author: Gregory M. Odegard
Publisher:
ISBN:
Category : Nanostructured materials
Languages : en
Pages : 20

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Book Description
In this study, a technique has been proposed for developing constitive models for polymer composite systems reinforced with single-walled carbon nanotubes (SWNT). Since the polymer molecules are on the same size scale as the nanotubes, the interaction at the polymer/nanotube interface is highly dependent on the local molecular structure and bonding. At these small length scales, the lattice structures of the nanotube and polymer chains cannot be be considered continuous, and the bulk mechanical properties of the SWNT/polymer composites can no longer be determined through traditional micromechanical approaches that are formulated using continuum mechanics. It is proposed herein that the nanotube, the local polymer near the nanotube, and the nanotube/polymer interface can be modeled as an effective continuum fiber using an equivalent-continuum modeling method.

Chemical and Biochemical Engineering

Chemical and Biochemical Engineering PDF Author: Ali Pourhashemi
Publisher: CRC Press
ISBN: 1482252430
Category : Medical
Languages : en
Pages : 302

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Book Description
This book facilitates the study of problematic chemicals in such applications as chemical fate modeling, chemical process design, and experimental design. This volume provides comprehensive coverage of modern biochemical engineering, detailing the basic concepts underlying the behavior of bioprocesses as well as advances in bioprocess and biochemical engineering science. It combines contemporary engineering science with relevant biological concepts in a comprehensive introduction to biochemical engineering. This book provides both a rigorous view and a more practical, understandable view of chemical compounds and biochemical engineering and their applications. Every section of the book has been expanded where relevant to take account of significant new discoveries and realizations of the importance of key concepts. Furthermore, emphases are placed on the underlying fundamentals and on acquisition of a broad and comprehensive grasp of the field as a whole.

Nanoengineering of Structural, Functional and Smart Materials

Nanoengineering of Structural, Functional and Smart Materials PDF Author: Mark J. Schulz
Publisher: CRC Press
ISBN: 0203491963
Category : Technology & Engineering
Languages : en
Pages : 740

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Book Description
In chapters contributed by 24 university & government laboratories, Nanoengineering of Structural, Functional, and Smart Materials combines wide-ranging research aimed at the development of multifunctional materials that are strong, lightweight, and versatile. This book explores promising and diverse approaches to the design of nanoscale

Characterization of Nanocomposites

Characterization of Nanocomposites PDF Author: Frank Abdi
Publisher: CRC Press
ISBN: 1315341247
Category : Science
Languages : en
Pages : 292

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Book Description
These days, advanced multiscale hybrid materials are being produced in the industry, studied by universities, and used in several applications. Unlike for macromaterials, it is difficult to obtain the physical, mechanical, electrical, and thermal properties of nanomaterials because of the scale. Designers, however, must have knowledge of these properties to perform any finite element analysis or durability and damage tolerance analysis. This is the book that brings this knowledge within easy reach. What makes the book unique is the fact that its approach that combines multiscale multiphysics and statistical analysis with multiscale progressive failure analysis. The combination gives a very powerful tool for minimizing tests, improving accuracy, and understanding the effect of the statistical nature of materials, in addition to the mechanics of advanced multiscale materials, all the way to failure. The book focuses on obtaining valid mechanical properties of nanocomposite materials by accurate prediction and observed physical tests, as well as by evaluation of test anomalies of advanced multiscale nanocomposites containing nanoparticles of different shapes, such as chopped fiber, spherical, and platelet, in polymeric, ceramic, and metallic materials. The prediction capability covers delamination, fracture toughness, impact resistance, conductivity, and fire resistance of nanocomposites. The methodology employs a high-fidelity procedure backed with comparison of predictions with test data for various types of static, fatigue, dynamic, and crack growth problems. Using the proposed approach, a good correlation between the simulation and experimental data is established.

In-Silico Approaches to Macromolecular Chemistry

In-Silico Approaches to Macromolecular Chemistry PDF Author: Minu Elizabeth Thomas
Publisher: Elsevier
ISBN: 0323909965
Category : Science
Languages : en
Pages : 628

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Book Description
Computational approaches offer researchers unique insights into the structure, characteristics, and properties of macromolecules. However, with applications across a broad range of areas, various methods have been developed for exploring macromolecules in in silico; therefore, it can be difficult for researchers to select the most appropriate method for their specific needs. Covering both biopolymers and synthetic polymers, In-Silico Approaches to Macromolecular Chemistry familiarizes readers with the theoretical tools and software appropriate for such studies. In addition to providing essential background knowledge on both computational tools and macromolecules, the book presents in-depth studies of in silico macromolecule chemistry, discusses and compares these with experimental studies, and highlights the future potential for such approaches. Written by specialists in their respective fields, this book helps students, researchers, and industry professionals gain a clear overview of the field, and furnishes them with the knowledge needed to understand and select the most appropriate tools for conducting and analyzing computational studies. Highlights in silico studies of both bio and synthetic macromolecules in one book Supports both learners and experts though a combination of detailed guidance and perspectives on the future potential for in silico approaches to macromolecules Familiarizes readers with theoretical tools and software helping them select the best approach for their specific needs

Mechanical Properties of Nanostructured Materials

Mechanical Properties of Nanostructured Materials PDF Author: Abdolhossein Fereidoon
Publisher: Xlibris Corporation
ISBN: 1524544116
Category : Computers
Languages : en
Pages : 143

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Book Description
Nowadays, with the improved abilities of computers, molecular modeling has become a powerful technique in computational chemistry with ever-increasing practical interests. At the moment, using effective algorithms along with powerful processors enables us to simulate systems, including thousands of atoms up to several microseconds. However, finding a balance between the computational costs and reliable results still remains a challenge. Two general approaches help us to reveal the behavior of these systems: quantum chemical calculations and molecular mechanics calculations. Quantum mechanics deals with physical phenomena as well as atoms behavior during chemical bonding and falls in the category of modern physics. In this book, two of the most practical quantum mechanics approaches are investigated: density functional theory (DFT) and density-functional tight-binding (DFTB).