Search Results for fiber length

This chapter discusses the properties and uses of fiber-reinforced composites. It also describes the effect of volume fraction and fiber length.

This chapter discusses the effect of fiber length and orientation on the strength and stiffness of discontinuous-fiber composites. It also describes several fabrication processes, including spray-up, compression molding, reaction injection molding, and injection molding.

This chapter discusses the ways in which the evolution of filament winding software systems has capitalized on the inherent flexibility of computer numerical controlled winding machines and enhanced their productivity. It provides a detailed discussion on different types of geometries that can be wound, from the simple to the highly complex, with insight into the limitations, advantages, and challenges of each. Components covered include classic axisymmetric parts (rings, pipes, driveshafts, pipe reducers, tapered shafts, closed-end pressure vessels, and storage tanks), nonround sections (aeromasts, airfoils, box sections, and fuselage sections), curved-axis parts (elbows, ducts), and special applications (tees). Basic winding concepts, such as band pattern, are discussed and explained, and some simple predictive formulae are introduced. The chapter also provides examples of programming various geometries using advanced software tools and discusses how various materials, such as rovings, tow-preg, prepreg tape, and woven materials, affect winding program generation.

Metal-matrix composites can operate at higher temperatures than their base metal counterparts and, unlike polymer-matrix composites, are nonflammable, do not outgas in a vacuum, and resist attack by solvents and fuels. They can also be tailored to provide greater strength and stiffness, among other properties, in preferred directions and locations. This chapter discusses the processes and procedures used in the production of fiber-reinforced aluminum and titanium metal-matrix composites. It explains how the length and orientation of reinforcing fibers affect the properties and processing characteristics of both aluminum and titanium composites. It also provides information on fiber-metal laminates and the use of different matrix metals and reinforcing materials.

This chapter discusses the properties and processing characteristics of glass, aramid, carbon, and ultra-high molecular weight polyethylene fibers and related product forms, including woven fabrics, prepreg, and reinforced mats. It also includes a review of fiber terminology as well as physical and mechanical property data for commercially important high-strength fibers.

This chapter outlines a method for mathematically describing fiber trajectories on a shell of revolution. After a short outline of the basic geometry of shells of revolution, the focus shifts to fiber trajectories and their characteristic metrics, angles, and vectors. Next, the chapter focuses on the determination of various kinds of curvatures that eventually lead to the derivation of (non-) geodesic fiber trajectories according to a predetermined coefficient of friction. It concludes with the analysis of nongeodesics on conical segments, annuli, and cylinders.

Unlike metals, in which fatigue failures are due to a single crack that grows to a critical length, the effects of fatigue in composites are much more distributed and varied. As the chapter explains, there are five major damage mechanisms that contribute to the progression of composite fatigue, those being matrix cracking, fiber breaking, crack coupling, delamination initiation, and delamination growth. The chapter describes each mechanism in detail along with related factors. It also discusses the primary differences between composites and metals, the effect of manufacturing defects, damage tolerance, and testing and certification.

This article describes in more detail the fundamental building-block level, atomic, then expands to a discussion of molecular considerations, intermolecular structures, and finally supermolecular issues. An explanation of important thermal, mechanical, and physical properties of engineering plastics and commodity plastics follows, and the final section briefly outlines the most common plastics manufacturing processes.

To ensure the proper application of plastics, one must keep in mind three factors that determine the appropriate end-use: material selection, processing, and design. This article begins by providing information on various factors pertinent to the anticipated use conditions of the article to be designed. This is followed by a discussion on several stages necessary to define the geometry of plastic parts. Details on the strength of and cost estimation for plastic parts are then provided. The article ends with a section providing information on the structure, properties, processing, and end-use applications of plastics.

Polymer-matrix composites are among the lightest structural materials in use today. They are also highly resistant to corrosion and fatigue and their load-carrying capabilities, such as strength and stiffness, can be tailored for specific applications. This chapter discusses the primary advantages and disadvantages of polymer-matrix composites, how they are produced, and how they perform in different applications. It describes the construction of laminates, the fibers and resins used, and the methods by which they are combined. It explains how strength, modulus, toughness, and high-temperature and corrosion behaviors are determined by the orientation, shape, and spacing of fibers, the number of plies, resin properties, and consolidation and forming methods. The chapter also covers secondary fabrication processes, such as thermoforming, machining, and joining, as well as production equipment and product forms, and include guidelines for optimizing tradeoffs when selecting fibers, resins, and production techniques.

This chapter discusses design and certification considerations, including materials and process selection, the building block approach to certification, design allowables, and design guidelines. It also includes information on damage tolerance and environmental sensitivity.

This chapter addresses the hardware requirements for filament winding, from elementary processing equipment to more advanced systems. The chapter describes the equipment, defines how it is best used, and presents real-life examples. It describes a helical horizontal filament winding machine system and a vertical winding machine. The chapter provides information on in-plane (polar) winders and several types of creels, namely stationary and no twist, rotating, braking, and combinations thereof. Comprehensive descriptions of mandrel designs used in filament winding are presented in text and illustration. The chapter also reviews process control of filament winding parameters, including for some specialized winding processes and unique component types.

This appendix is a compilation of terms and definitions related to composite filament winding.

This chapter reviews the development of filament winding systems and the automated processes used in state-of-the-art filament winding facilities. It first provides a description on the early stages of modern filament winding, followed by brief information on the advances of filament winding in the computer age. Then, the chapter discusses the requirements for filament winding in manufacturing oil and gas industry components and in high-volume production of sporting goods, propane tanks, and curing ovens. The chapter concludes with examples of the versatility of filament winding in producing complex parts.

This chapter presents the fundamentals of tensile testing of fiber-reinforced polymer composites. Basic tensile testing of polymer composites is divided into lamina and laminate testing. The chapter focuses on tensile testing of laminates. It discusses the most common tensile test methods that have been standardized for fiber-reinforced composite materials. It also briefly reviews considerations in tensile testing of metal-matrix composites.