nach oben

2013 | Buch

Kapitel lesen Erstes Kapitel lesen

Carbon Nanotube Enhanced Aerospace Composite Materials

A New Generation of Multifunctional Hybrid Structural Composites

herausgegeben von: A. Paipetis, V. Kostopoulos

Verlag: Springer Netherlands

Buchreihe : Solid Mechanics and Its Applications

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

Einloggen, um Zugang zu erhalten

Über dieses Buch

The well documented increase in the use of high performance composites as structural materials in aerospace components is continuously raising the demands in terms of dynamic performance, structural integrity, reliable life monitoring systems and adaptive actuating abilities. Current technologies address the above issues separately; material property tailoring and custom design practices aim to the enhancement of dynamic and damage tolerance characteristics, whereas life monitoring and actuation is performed with embedded sensors that may be detrimental to the structural integrity of the component.

This publication explores the unique properties of carbon nanotubes (CNT) as an additive in the matrix of Fibre Reinforced Plastics (FRP), for producing structural composites with improved mechanical performance as well as sensing/actuating capabilities. The successful combination of the CNT properties and existing sensing actuating technologies leads to the realization of a multifunctional FRP structure. The current volume presents the state of the art research in this field.

The contributions cover all the aspects of the novel composite systems, i.e. modeling from nano to macro scale, enhancement of structural efficiency, dispersion and manufacturing, integral health monitoring abilities, Raman monitoring, as well as the capabilities that ordered carbon nanotube arrays offer in terms of sensing and/or actuating in aerospace composites.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Carbon Nanotubes for Novel Hybrid Structural Composites with Enhanced Damage Tolerance and Self-Sensing/Actuating Abilities

Abstract

Damage tolerance, reliability, and sensing/actuating abilities are within the forefront of research for aerospace composite materials and structures. The scope of this chapter is to identify the potential application of incorporating carbon nanotubes (CNTs) in novel hybrid material systems. CNTs may be employed as an additive in the matrix of Fibre Reinforced Plastics (FRP) for producing structural composites with improved mechanical performance as well as sensing/actuating capabilities. The novel multi-scale reinforced composite materials are by definition multifunctional as they combine better structural performance with smart features that may include strain monitoring, damage sensing and even actuation capabilities. This introductory chapter provides an overview of the concepts and technologies related to the hierarchical composite systems that will be elaborated in the following chapters, i.e. modelling, enhancement of structural efficiency, dispersion and manufacturing, integral health monitoring abilities, Raman monitoring, as well as the capabilities that ordered carbon nanotube arrays offer in terms of sensing and/or actuating in aerospace composites.

A. S. Paipetis, V. Kostopoulos

Chapter 2. On the Use of Electrical Conductivity for the Assessment of Damage in Carbon Nanotubes Enhanced Aerospace Composites

Abstract

In this chapter a review on the research of nano-enabled self-sensing structural composite materials is performed. The self-sensing concept is attained by exploiting the intrinsic electrical properties of a structural composite material. Recent research on self-sensing was stimulated by the introduction of nanotechnology in the field of composite materials. Nano-scale fillers such as carbon nanotubes (CNTs), due to their excellent electrical properties, may offer benefits of additional reinforcing phase acting at the nano-scale. The research may be divided into two distinctive categories depending on the type of fibre reinforcement. One category is the research that used electrically non-conductive glass fibre reinforced plastics (GFRP) where carbon nanotubes in various forms are incorporated into the composite to enable sensing. The other category is the research that used electrical conductive carbon fibre reinforced plastics (CFRP) where the carbon nanotubes in various forms are used to enhance the electrical sensing capabilities of the composite.

Antonios I. Vavouliotis, Vassilis Kostopoulos

Chapter 3. Carbon Nanotube Structures with Sensing and Actuating Capabilities

Abstract

We describe carbon nanotube (CNT) structures which are used as mechanical sensors, electromechanical actuators and shape memory materials. These structures include CNT mats and fibres of aligned CNTs. Mechanical sensors are based on the piezo-resistivity of the investigated CNT structures. They can be used as embedded sensors for sensing and damage monitoring of composites. CNT can also be used for novel actuator technologies. Indeed CNTs deform in response to charge injection and electrostatic phenomena. They can be stimulated under the form of electrodes in a given electrolyte. CNT structures can generate a large stress because of their stiffness. In other classes of actuating materials, carbon nanotubes can be used as fillers of shape memory polymers (SMPs). SMPs have applications in packaging, biomedical devices, heat shrink tubing, deployable structures, etc. CNTs are ideal materials to improve the stiffness of shape memory polymers, which is critical for achieving large stress recovery. Their electrical conductivity is of particular interest in the engineering of SMPs which can be heated via Joule’s heating and directly stimulated by an electrical current. We review in this chapter the properties of these new functional materials and highlight their potential for future applications.

C. Jaillet, N. D. Alexopoulos, P. Poulin

Chapter 4. Mechanical Dispersion Methods for Carbon Nanotubes in Aerospace Composite Matrix Systems

Abstract

Utilizing the reinforcing effects CNTs might bring requires techniques resulting in separated and uniformly dispersed CNTs in the matrix resin system. Mechanical dispersion methods are available in various types. A review of the literature of these dispersion techniques and the accompanying dispersion mechanisms is presented. Starting with a general overview of problems that occur by modifying matrix materials with CNTs and a short description of pre-dispersion and additive assisted dispersion, the main focus is on mixing and milling techniques. Furthermore, the rapid expansion of supercritical suspensions and ultrasonication are discussed. Finally, possible ways of combining dispersive methods and controlling the dispersion quality are presented.

Sergiy Grishchuk, Ralf Schledjewski

Chapter 5. Chemical Functionalization of Carbon Nanotubes for Dispersion in Epoxy Matrices

Abstract

The remarkable physical properties of carbon nanotubes and their versatile chemical reactivity leading to various types of surface organo-functionalization were the main reasons why CNTs have become one of the most important types of nano-additives for the development of novel polymer (including epoxy) nanocomposites with improved and sometimes unique properties. The present chapter deals with the organo-functionalization of carbon nanotubes and the preparation of the respective epoxy – CNT nanocomposites. The effect of functionalization on dispersion of CNTs and on the final properties of the nanocomposites is discussed, while emphasis is given on the reactivity of the functional groups and their participation in the curing process of epoxy resins.

Dimitrios J. Giliopoulos, Kostas S. Triantafyllidis, Dimitrios Gournis

Chapter 6. Stress Induced Changes in the Raman Spectrum of Carbon Nanostructures and Their Composites

Abstract

Raman spectroscopy of Carbon nanostructures is fundamental in characterising the morphology and the interaction of the nanostructure with the environment. This work provides an outline of the Raman Vibrational modes for graphitic structures starting from graphite fibres, to single-wall carbon nanotubes to multiwall carbon nanotubes and finally to Single- and Multi-layer Graphene. Following a brief outline of the dependence of the force constant on applied deformation, the stress induced changes in the Raman spectrum of graphitic structures are subsequently discussed with a view to elucidating the reinforcing ability of the CNTs in a matrix and assessing the stress transfer at the CNT matrix interface. The possibilities of employing CNTs as stress sensors in composite materials are also presented.

A. S. Paipetis

Chapter 7. Mechanical and Electrical Response Models of Carbon Nanotubes

Abstract

Carbon nanotubes have remarkable mechanical and electrical properties. One promising feature is their electrical resistance that strongly depends on mechanical deformation. This, in combination with the fact that nanotubes can be dispersed into polymeric matrices, makes them ideal constituents for the development of novel multifunctional materials and devices. When dispersed into an insulating polymer, nanotubes are known to induce conductive behavior to the composite. This is attributed to the formation of conductive nanotube networks due to percolation. When a nanocomposite is mechanically deformed, load is transferred to the nanotubes, as well. As they deform and rearrange, their electrical properties change and the percolation networks are distorted. This effect is studied in this chapter using three models: (i) an atomistic molecular mechanics approach for prediction of the mechanical response of carbon nanotubes, (ii) a subatomic tight-binding approach for prediction of the piezeoresistive response of individual carbon nanotubes, and (iii) a homogenized microscale model for prediction of the piezoresistive response of carbon nanotube doped insulating polymers. Results seem to be in agreement with experimental results for small deformations.

T. C. Theodosiou, D. A. Saravanos

Chapter 8. Improved Damage Tolerance Properties of Aerospace Structures by the Addition of Carbon Nanotubes

Abstract

The potential use of carbon nanotubes (CNTs) in aerospace structures is considered in this chapter. Various studies are presented on how carbon nanotubes may be the driving force of a new generation of aerospace structures with superior damage tolerance properties, which in turn will lead to novel composite structures for the aerospace industry. This chapter examines the inclusion of CNTs in aerospace grade resins and their reinforcing mechanisms. The conclusion reached is that the main reinforcing mechanisms of carbon nanotubes are: fibre breakage, fibre pull-out, crack bridging and crazing. These are responsible for the improvement of the mechanical properties of composite materials and their structures. In other words, the use of carbon nanotubes in aerospace composite structures has been proven to increase fracture toughness, impact strength, post-impact properties and the fatigue life of composites, all these attributes making them more damage tolerant. Finally, a new generation of fibres and fabrics with CNTs grafted or grown on them are presented. They are expected to play a key role in evolution of aerospace composite structures, overcoming any processing issues that have risen due to high CNT-polymer viscosities.

Petros Karapappas, Panayota Tsotra

Chapter 9. Environmental Degradation of Carbon Nanotube Hybrid Aerospace Composites

Abstract

This chapter focuses on the environmental response of carbon fibre-reinforced epoxy composites, where the matrix has been modified with carbon nanotubes. These newly developed hybrid aerospace systems have been recently introduced as alternatives to conventional high performance polymer composites due to their improved mechanical properties, toughness and damage sensing abilities as discussed in detail in previous chapters. First an attempt is made to outline the conditions that lead to environmental degradation specifically in aerospace environments. Next to that the response of typical aerospace composites to these environments is discussed. Following, the benefits and challenges in using hybrid aerospace composites in in-service conditions is presented. The degradation of hybrid composites due to exposure on hydro/hygrothermal loadings and galvanic corrosion is presented based on preliminary results. In this section, the focus is on epoxy based composites reinforced with carbon fibres. Matrix modification of these systems is provided by the addition of carbon nanotubes.

Nektaria-Marianthi Barkoula

Titel: Carbon Nanotube Enhanced Aerospace Composite Materials
herausgegeben von: A. Paipetis
V. Kostopoulos
Verlag: Springer Netherlands
Electronic ISBN: 978-94-007-4246-8
Print ISBN: 978-94-007-4245-1
DOI: https://doi.org/10.1007/978-94-007-4246-8

Premium Partner

Marktübersichten

Die im Laufe eines Jahres in der „adhäsion“ veröffentlichten Marktübersichten helfen Anwendern verschiedenster Branchen, sich einen gezielten Überblick über Lieferantenangebote zu verschaffen.

Zur Marktübersicht