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.

Polymer nanocomposites are a class of material with a great deal of promise for potential applications in various industries ranging from construction to aerospace. The main difference between polymeric nanocomposites and conventional composites is the filler that is being used for reinforcement. In the nanocomposites the reinforcement is on the order of nanometer that leads to a very different final macroscopic property. Due to this unique feature polymeric nanocomposites have been studied exclusively in the last decade using various nanofillers such as minerals, sheets or fibers. This books focuses on the preparation and property analysis of polymer nanocomposites with CNTs (fibers) as nano fillers. The book has been divided into three sections. The first section deals with fabrication and property analysis of new carbon nanotube structures. The second section deals with preparation and characterization of polymer composites with CNTs followed by the various applications of polymers with CNTs in the third section.

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

Fiber-reinforced Nanocomposites: Fundamentals and Applications explores the fundamental concepts and emerging applications of fiber-reinforced nanocomposites in the automobile, aerospace, transportation, construction, sporting goods, optics, electronics, acoustics and environmental sector. In addition, the book provides a detailed overview of the properties of fiber-reinforced nanocomposites, including discussion on embedding these high-strength fibers in matrices. Due to the mismatch in structure, density, strain and thermal expansion coefficients between matrix and fibers, their thermo-mechanical properties strongly depend not only on the preparative methods, but also on the interaction between reinforcing phase and matrix phase. This book offers a concise overview of these advances and how they are leading to the creation of stronger, more durable classes of nanocomposite materials. - Explores the interaction between fiber, nanoreinforcers and matrices at the nanoscale - Shows how the properties of fiber-enforced nanocomposites are ideal for use for a variety of consumer products - Outlines the major challenges to creating fiber-reinforced nanocomposites effectively

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.

Polymer nanocomposites are a class of material with a great deal of promise for potential applications in various industries ranging from construction to aerospace. The main difference between polymeric nanocomposites and conventional composites is the filler that is being used for reinforcement. In the nanocomposites the reinforcement is on the order of nanometer that leads to a very different final macroscopic property. Due to this unique feature polymeric nanocomposites have been studied exclusively in the last decade using various nanofillers such as minerals, sheets or fibers. This books focuses on the preparation and property analysis of polymer nanocomposites with CNTs (fibers) as nano fillers. The book has been divided into three sections. The first section deals with fabrication and property analysis of new carbon nanotube structures. The second section deals with preparation and characterization of polymer composites with CNTs followed by the various applications of polymers with CNTs in the third section.

Carbon nanotubes (CNTs) have amazing properties and a key way to take advantage of this is by incorporating nanotubes into a matrix to build composite materials. The best candidates for this task are undoubtedly polymers. Almost every characteristic of a polymer can be significantly enhanced by adding carbon nanotubes and as a result, new potential applications of carbon nanotube enhanced polymer composites are discovered every day. However, before carbon nanotube enhanced polymer composites become commonplace there are some tough challenges that need to be overcome. This book reviews the status of worldwide research in both single-walled and multi-walled carbon nanotube based composites. It serves as a practical guide on carbon nanotube based composites and a reference to students and researchers from the academia and industry.

In this study, a technique is presented for developing constitutive models for polymer composite systems reinforced with single-walled carbon nanotubes (SWNT). Because 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 considered continuous, and the bulk mechanical properties can no longer be determined through the traditional micromechanical approaches that are formulated by 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. The micromechanical analyses for the prediction of bulk mechanical properties of SWNT/polymer composites with various nanotube lengths, concentrations, and orientations. As an example, the proposed approach is used for the constitutive modeling of two SWNT/polyimide composite systems.

Discovered in the twentieth century, carbon nanotubes (CNT) were an integral part of science and industry by the beginning of the twenty first century, revolutionizing chemistry, physics, and materials science. More recent advances in carbon nanotube production methods have resulted in a tremendous push to incorporate CNTs into polymer matrices. Al

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.