The book encompasses 12 chapters, containing 1130 citations, 167 figures, and 36 tables.
Ernest K. Condon III and Paul J. Jonas
Wichita State University,
National Institute for Aviation Research, Wichita, KS, USA
This chapter provides an overview of the various electromagnetic effects design areas involved in design, test, and operation of vehicles and equipment built with composite materials. These design areas determine how well composite materials perform in electromagnetic energy fields and any indirect effects to any systems and equipment on or within. Specifically, the focus will be on the effects that the use of composite materials has on the various electromagnetic effects design areas. The various material properties that contribute to the effects will be addressed from the standpoint of quantification early in a design phase through testing and analysis, design/mitigation choices, and current material and mitigation trends related to these properties. The terminology in this chapter relates the application to aircraft. However, the concepts are also directly applicable to any other complete systems, such as wind turbines and buildings. Note that many of these design areas are interrelated. Be sure to consider all the design areas and their effects in order to get a system-wide view of the interactions.
Gasser F. Abdelal
Queen's University Belfast, Belfast, UK
This chapter presents state of the art numerical and experimental testing procedures to investigate the efficiency of lightning strike protection (LSP) systems. Thus, a coupled thermal-electrical finite element analysis (FEA) procedure is proposed to enable the investigation of the design variables that control lightning strike damage in Graphite/Epoxy composites. The major contribution of this chapter is the formulation and verification of temperature dependent material properties, a key attribute not considered within previous literature. The proposed procedure is applied to a test specimen and the results are verified against published experimental data, illustrating the accuracy and computational cost of lightning strike simulation and the requirement for temperature dependent material properties. The procedure is then applied to a number of practical LSP systems and the simulation results are used to further understand and quantify the physical behavior that minimizes material damage. Further, this chapter investigates using multiphysics (magnetic, electric, heat transfer, and computational fluid dynamics) to model the free burning electric arc (plasma) between the cathode and the anode during lightning strike of a composite, providing an estimate of the damage caused by resistive heating and overpressure.
Timothy L. Norman
Cedarville University, Cedarville, Ohio USA, and
C. T. Sun
Purdue University, West Lafayette, IN, USA
In-service use of laminated composite materials commonly includes impact loading events including handling, tool drops, and foreign object impacts such as runway debris. Low velocity impacts often result in internal damage that is undetectable by visual inspection. Internal laminate damage can grow with fluctuating load and may severely degrade residual strength and stability of a structure, especially under compression loading. This chapter addresses the issues related to foreign body impact damage of composites. The chapter begins with fundamental definitions on impact of composites and then explores impact testing and post-impact evaluation procedures. Failure modes and post-impact residual properties will also be examined. The chapter concludes with a look at modern approaches used to improve the impact response of composites.
Edmond Tobin, Aidan Cloonan, and Trevor Young
University of Limerik, Republic of Ireland
Repeated impacts of liquid droplets, solid particles or cavitation can cause significant damage to composite materials removing both matrix and fiber material. The addition of fillers and nanoscale constituents can improve the erosion resistance and service life. Droplet erosion mechanisms differ from those of solid particle erosion which leads to a trade-off for the desired material properties. Impact angle and velocity of erodent are parameters which will affect the damage mechanisms. The following sections outline the historical and current norms of liquid droplet erosion (LDE) and solid particle erosion (SPE) testing. Results and data from test campaigns on composite materials are also presented.
Edith R. Fotsing, Annie Ross, and Edu Ruiz
'Ecole Politechnique de Montr'eal, Montr'eal, Canada
The main functionality of composites, namely their high structural stiffness to weight ratio, facilitates the propagation of mechanical and acoustic vibration leading to discomfort and sometimes to mechanical damage. Despite inherent damping capacity, energy dissipation in composites is insufficient for high performance applications. Therefore, new materials and manufacturing processes must be developed to improve the damping performance of high performance composite structures. In this chapter, structural-borne vibration and its relationship to noise are described. The viscoelasticity of composite materials is treated and the techniques used to characterize fundamental material properties are presented. The classical methods for reducing vibration transmission along a structure are discussed. Novel techniques used for vibration damping and noise reduction of composite structures are also presented and practical examples are given. Analytical modeling of novel damping techniques is described.
University of Aveiro, Aveiro, Portugal
Passive damping treatments using viscoelastic materials (VEM) represent a common and valuable solution for vibration control of light and thin structures. The introduction of thin layers of polymeric-based materials with the ability to dissipate deformation energy as heat has been broadly explored through the form of surface damping treatments that can be applied onto panels and beams. This chapter aims to provide a comprehensive overview on the most important passive vibration control techniques for large, lightweight structures. Among these passive control techniques, a complete description is presented for viscoelastic damping treatments, which represent a significant segment of the passive damping treatments applied to light metallic and composite components. The main issues on viscoelastic material characterization and modeling, finite element simulation, and experimental analysis are discussed. The design and optimization of viscoelastic damping treatments are also addressed, and the most important optimal design rules are presented. Finally, the most significant trends for these damping mechanisms are discussed.
Kathryn Mireles and Micheal R. Kessler
Washington State University, Pullman, WA, USA
By mimicking biological healing processes in which the onset of damage triggers a repairing mechanism, the main failure modes of composites such as micro-cracking may be prevented before macroscopic damage occurs. An introduction to self-healing polymers and their inclusion in structural composites is provided in this chapter in four main sections: (1) An introduction to the design and chemistry of self-healing materials, (2) a review of self-healing structural polymer composites, (3) a description of the approaches used to evaluate and characterize self-healing polymers and composites, and (4) a discussion of the challenges and future directions in this field.
Christopher J. Hansen
University of Massachusetts Lowell, Lowell, MA, USA
Embedded microvascular networks and fluid transport through these pathways enable unique fluid-mediated functionalities within composite structures. Biological inspiration for synthetic microvascular analogs guides the design of vascular networks and systems tailored for specific structures and subcomponents, and which are subject to competing physical constraints and functional objectives. Non-structural functionalities enabled by microvascular fluid transport include self-healing of repetitive fracture damage, thermal regulation of temperature-sensitive regions, structural health monitoring, structural fluid storage, and recovery of macroscale material loss.
Beihang University, Beijing, China, and
Florida State University, Tallahassee, FL, USA
Polymer nanocomposites have attracted interest as barrier materials in packaging and protective applications, enabling higher performance in terms of low gas permeability. The addition of nanoplatelets effectively enhances tortuosity, leading to lower gas permeabilities. This chapter reviews gas permeation behavior in polymeric materials, conventional processing methods of polymer nanocomposites, and corresponding gas permeation theory. Barrier nanoplatelets such as silicate clay and graphene, innovative processing technology such as layer-by-layer deposition, and multifunctional characteristics of polymer nanocomposites are discussed. The factors influencing barrier properties and the corresponding improvement approaches are emphasized. Some applications for gas storage tanks, electronics, food packaging, and anti-corrosion coating are also presented.
University of Ulster, Newtownabbey Co, Antrim, UK, and
University of North Carolina at Charlotte, Charlotte, NC, USA
This chapter deals with the fire safety of multifunctional composite materials. The chapter starts with a brief description of possible fire hazards that may arise from the use of multifunctional polymer composite materials and relevant fire safety regulations, explaining why fire safety of composites is important. Following an introduction of the combustion mechanism, fire safety strategy is introduced. It then presents properties used to evaluate fire performance of multifunctional composite materials. Lastly, it provides details about fire retardants for improving the fire safety of multifunctional polymer composites.
Maurizio Natali, Luigi Torre, and Jos'e Maria Kenny
University of Perugia, Perugia, Italy
Ablative materials play a vital role for the entire aerospace industry. Although some non-polymeric materials have been successfully used as ablatives, polymer ablatives (PA) represent the most versatile class of thermal protection system (TPS) materials. Compared with oxide, inorganic polymer, and metal based TPS materials, PAs have some intrinsic advantages, such as high heat shock resistance and low density. PAs are used to manufacture TPS for protection of vehicles and probes during the hypersonic flight through a planetary atmosphere and are also used in the production of chemical propulsion systems such as liquid and solid rocket motors. In this chapter, the state of the art of traditional and nanostructured polymeric ablatives will be reviewed.
Tomas I. Muchenik and Ever J. Barbero
West Virginia University, Morgantown, WV, USA
Magnetoelectric composites provide an electrical output in response to a magnetic input, and vice versa. A mechanical input (deformation) also yields a magnetic and electric response. The composite combines two phases: piezoelectric and magnetostrictive. Neither phase has magnetoelectric response, but when combined into a composite, the new ``material'' displays strong magnetoelectric response at room temperature. The coupling is provided by deformation, which both phases share when combined into a composite material. The response can be quantified in terms of the properties of the phases, their relative volumetric participation, and the geometry of the device, as described in this chapter. Magnetoelectric composites are multifunctional in the sense that they can both sense and harvest energy, and they can do that from multiple sources, i.e., magnetic, electric, and deformation fields.
A review of major developments in this field is presented in Section 12.1, followed by a summary of the fundamental concepts and equations for the three physics involved in this chapter, namely electrostatics, magnetostatics, and elasticity. The nomenclature is presented in Table 12.1. Intrinsic and extrinsic properties are discussed in Section 12.6 and 12.7, respectively, followed by a summary and conclusions.