Carbon-Nanotube-Reinforced-Polymer-Composite (CNRPC) materials have generated widespread interest over the last several years in practical engineering applications, such as aeronautical and aerospace engineering structures. However, studies still need to be carried out to characterize their mechanical properties, especially the dynamic properties, and the effects of defects on the mechanical properties. Experimental investigations intended for this purpose have limitations and, in most cases, reliable cost-effective experimental work could not be carried out. Computational modelling and simulation encompassing multiscale material behavior provide an alternate approach in this regard to characterize the material behavior. A probabilistic approach serves as a suitable approach to characterize the effects of material and structural defects. The present thesis reports the development of a computational framework of the Representative Volume Element (RVE) of a CNRPC material model to determine its static and dynamic responses, and also for the evaluation of its static and dynamic reliabilities based on a probabilistic characterization approach. A 3D multiscale finite element model of the RVE of the nanocomposite material consisting of a polymer matrix, a Single-Walled-Carbon-Nanotube (SWCN) and an interface region has been constructed for this purpose. The multiscale modeling is performed in terms of using different theories and corresponding strain energies to model the individual parts of the RVE of the CNRPC material. The macroscale continuum mechanics is used for the polymer matrix, the mesoscale mechanics is used for the interface region, and the nanoscale-level atomistic mechanics is used for the SWCN. The polymer matrix is modeled using the Mooney-Rivlin strain energy function to calculate its non-linear response, while the interface region is modeled via the van der Waals links. The SWCN is first modeled as a space frame structure by using the Morse potential, and then as a thin shell based on a suitable shell theory. For this purpose, the suitability and the accuracy of popular shell theories for use in the multiscale model of the RVE are assessed.

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

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.

High thermal conductivity of carbon nanotubes has motivated us to study and understand the thermal mechanisms in nanocomposites. Though several theoretical models predict a high thermal conductivity for CNT reinforced polymer composites, the experimental validation are not so encouraging. A finite element model of MWNT reinforced nanocomposite is developed based on continuum mechanics approach. The finite element model is a representative volume element (RVE) with single MWNT inclusion. The inclusion is modeled based on the continuum model of MWNT as effective solid fiber [22]. The interface resistance between the nanotube and the matrix material is modeled using thermal contact elements. The finite element analysis was carried out keeping volume fraction of MWNT fibers as constant and varying three important parameters which influences the effective thermal conductivity. Analysis with varying volume fractions of CNT fibers was also carried out to study the influence of volume fraction. The results obtained were in agreeable range with the theoretical calculations made based on the work of Bagchi and Nomura [22]. The effective thermal conductivity of MWNT reinforced nanocomposites with MWNTs of high aspect ratios showed gradual increase in conductivity with increase in length while it showed a drastic decrease in effective thermal conductivity with increase in the diameter of the MWNT inclusion. The finite element analysis showed that the interface resistance between the nanotube and the matrix material does not affect effective thermal conductivity noticeably which is contradictory with few theoretical models which attribute interface resistance for lower than expected effective thermal conductivity. The analysis predicts linear increase of effective thermal conductivity with increase in volume fraction of the MWNT fibers in matrix material; this is also in accordance with the theoretical model. The above analysis also validates the use of finite element approach based on continuum mechanics in studying the overall behavior of the nanocomposites.

This book explains uncertainty analysis for finite elements and general nonlinear problems. It starts with the fundamentals of the topic and progresses to complex methods through 9 chapters. Each chapter focuses on a specific, relevant topic and provides information in a structured reading format for advanced learners. The author explains different models relevant to the topic where applicable, in an effort to cover the diverse aspects of mathematical analysis. Topics covered in the book include: - Nonlinear stochastic finite element methods - Reliability calculations - Static analysis of interval finite element - Linear and nonlinear vibration analysis - Stochastic, random, fuzzy and mixed fields - Mixed finite element analysis Uncertainty Analysis in Finite Elements Models is an ideal reference for advanced courses in mathematical analysis and engineering that require students to understand the basics of uncertainty analysis and basic reliability calculations.

Experimental Characterization, Predictive Mechanical and Thermal Modeling of Nanostructures and Their Polymer Composite focuses on the recent observations and predictions regarding the size-dependent mechanical properties, material properties and processing issues of carbon nanotubes (CNTs) and other nanostructured materials. The book takes various approaches, including dedicated characterization methods, theoretical approaches and computer simulations, providing a detailed examination of the fundamental mechanisms governing the deviations of the properties of CNTs and other nanostructured materials. The book explores their applications in materials science, mechanics, engineering, chemistry and physics due to their unique and appealing properties. The use of such materials is, however, still largely limited due to the difficulty in tuning their properties and morphological and structural features. - Presents a thorough discussion on how to effectively model the properties of carbon nanotubes and their polymer nanocomposites - Includes a size-dependent analysis of properties and multiscale modeling - Outlines the fundamentals and procedures of computational modeling as it is applied to carbon nanotubes and other nanomaterials

Fiber composite materials are ideal engineered materials to carry loads and stresses in the fiber direction due to their high in-plane specific mechanical properties. However, premature failure due to low transverse mechanical properties constitutes a fundamental weakness of composites. A solution to this problem is being addressed through the creation of a nano-reinforced laminated composite (NRLC) materials where carbon nanotubes (CNTs) are grown on the surface of the fiber filaments to improve the matrix-dominated properties. The carbon nanotubes increase the effective diameter of the fiber and provide a much larger interface area for the polymeric matrix to wet the fiber. The objective of this thesis work is to numerically predict the elastic properties of these nano-reinforced fiber composites. Finite Element Method (FEM) is used to evaluate the effective mechanical properties employing a 2D and 3D cylindrical representative volume element (RVE) based on multiscale modeling approach. In continuum mechanics, perfect bonding is assumed between the carbon fiber and the polymer matrix and between the carbon nanotubes and the polymer matrix. In the multiscale modeling approach in this work, cohesive zone approach is employed to model the interface between carbon fiber and polymer matrix and between the CNTs and the polymer matrix. Traction-displacement plots obtained from molecular dynamics simulations are used to derive the constitutive properties of the cohesive zone material model used for CNT-Polymer interface. For NRLC, the cohesive zone material model properties are assumed based on the information found in the literature. Effective material constants are extracted from the solutions of the RVE for different loading cases using theory of elasticity of isotropic and transversely isotropic materials. Experimental mechanical characterization data is used for correlation and validation of numerical results. It is observed that the cohesive zone material model is capable of capturing the interface behavioral details and provides more realistic results for the mechanical response of composite materials. Experimental results show that the potential improvement in matrix-dominated properties of the NRLC suggested by the numerical study can be realized only with the availability of improved and sophisticated NRLC fabrication techniques.

From the Foreword, written by legendary nano pioneer M. Meyyappan, Chief Scientist for Exploration Technology NASA Ames Research Center, Moffett Field, California, USA: "...there is critical need for a book to summarize the status of the field but more importantly to lay out the principles behind the technology. This is what Professor Arvind Agarwal and his co-workers ... have done here." Carbon Nanotubes: Reinforced Metal Matrix Composites reflects the authors’ desire to share the benefits of nanotechnology with the masses by developing metal matrix carbon nanotube (MM-CNT) composites for large-scale applications. Multiwall carbon nanotubes can now be produced on a large scale and at a significantly reduced cost. The book explores potential applications and applies the author’s own research to highlight critical developmental issues for different MM-CNT composites—and then outline novel solutions. With this problem-solving approach, the book explores: Advantages, limitations, and the evolution of processing techniques used for MM-CNT composites Characterization techniques unique to the study of MM-CNT composites—and the limitations of these methods Existing research on different MM-CNT composites, presented in useful tables that include composition, processing method, quality of CNT dispersion, and properties The micro-mechanical strengthening that results from adding CNT The applicability of micro-mechanics models in MM-CNT composites Significance of chemical stability for carbon nanotubes in the metal matrix as a function of processing, and its impact on CNT/metal interface and mechanical properties Computational studies that have not been sufficiently covered although they are essential to research and development The critical issue of CNT dispersion in the metal matrix, as well as a unique way to quantify CNT distribution and subsequently improve control of the processing parameters for obtaining improved properties Carbon Nanotubes: Reinforced Metal Matrix Composites paints a vivid picture of scientific and application achievements in this field. Exploring the mechanisms through which CNTs are enhancing the properties of different metal-based composites, the authors provide a roadmap to help researchers develop MM-CNT composites and choose potential materials for use in emerging areas of technology.

Carbon Nanotube Reinforced Composites introduces a wide audience of engineers, scientists and product designers to this important and rapidly expanding class of high performance composites. Dr Loos provides readers with the scientific fundamentals of carbon nanotubes (CNTs), CNT composites and nanotechnology in a way which will enable them to understand the performance, capability and potential of the materials under discussion. He also investigates how CNT reinforcement can be used to enhance the mechanical, electrical and thermal properties of polymer composites. Production methods, processing technologies and applications are fully examined, with reference to relevant patents. Finally, health and safety issues related to the use of CNTs are investigated. Dr. Loos compares the theoretical expectations of using CNTs to the results obtained in labs, and explains the reasons for the discrepancy between theoretical and experimental results. This approach makes the book an essential reference and practical guide for engineers and product developers working with reinforced polymers – as well as researchers and students in polymer science, materials and nanotechnology. A wealth of applications information is included, taken from the wide range of industry sectors utilizing CNT reinforced composites, such as energy, coatings, defense, electronics, medical devices, and high performance sports equipment. - Introduces a wide range of readers involved in plastics engineering, product design and manufacturing to the relevant topics in nano-science, nanotechnology, nanotubes and composites. - Assesses effects of CNTs as reinforcing agents, both in a materials context and an applications setting. - Focuses on applications aspects – performance, cost, health and safety, etc – for a wide range of industry sectors, e.g. energy, coatings, defense, electronics, medical devices, high performance sports equipment, etc.

The accessible compendium of polymers in carbon nanotubes (CNTs) Carbon nanotubes (CNTs)—extremely thin tubes only a few nanometers in diameter but able to attain lengths thousands of times greater—are prime candidates for use in the development of polymer composite materials. Bringing together thousands of disparate research works, Carbon Nanotube-Polymer Composites: Manufacture, Properties, and Applications covers CNT-polymers from synthesis to potential applications, presenting the basic science and engineering of this dynamic and complex area in an accessible, readable way. Designed to be of use to polymer scientists, engineers, chemists, physicists, and materials scientists, the book covers carbon nanotube fundamentals to help polymer experts understand CNTs, and polymer physics to help those in the CNT field, making it an invaluable resource for anyone working with CNT-polymer composites. Detailed chapters describe the mechanical, rheological, electrical, and thermal properties of carbon nanotube-polymer composites. Including a glossary that defines key terms, Carbon Nanotube-Polymer Composites is essential reading for anyone looking to gain a fundamental understanding of CNTs and polymers, as well as potential and current applications, including electronics (shielding and transparent electrodes), flame retardants, and electromechanics (sensors and actuators), and their challenges.