Discontinuous Fibre Reinforced Composites

This book provides a simple and unified approach to the mechanics of discontinuous-fibre reinforced composites, and introduces readers as generally as possible to the key concepts regarding the mechanics of elastic stress transfer, intermediate modes of stress transfer, plastic stress transfer, fibre pull-out, fibre fragmentation and matrix rupture. These concepts are subsequently applied to progressive stages of the loading process, through to the composite fractures. The book offers a valuable guide for advanced undergraduate and graduate students attending lecture courses on fibre composites. It is also intended for beginning researchers who wish to develop deeper insights into how discontinuous fibre provides reinforcement to composites, and for engineers, particularly those who wish to apply the concepts presented here to design and develop discontinuous-fibre reinforced composites.

There are many books on composite material analysis, but most cover mainly continuous fiber materials, rather than those filled with discontinuous fibers, which are particularly attractive for large-volume and low-cost applications. This book provides the theoretical and practical background to design and use discontinuous fiber-reinforced polymer materials, with an emphasis on structural parts for the automotive industry. Moreover, the product of years of collaborative work between industry and academia is presented in an easy-to-use, comprehensive manner. The information provided makes it possible for someone with an engineering background to understand the micromechanics of discontinuous fiber-reinforced materials and, hence, analyze the structural performance of components designed with such materials. The book employs a practical approach to cover the key, unique capabilities that are critical for a successful structural analysis of discontinuous fiber-reinforced polymer structures: -Process simulation to estimate the condition of fibers in the finished parts, i.e., fiber length, orientation, and concentration -Capability to measure micro structure, i.e., fiber length distribution, fiber orientation tensors, and fiber concentration, etc. -Estimation of material properties in the part based on fiber condition, as well as environmental conditions such as temperature A broad range of areas is included, such as joining and assembly.

This book is a printed edition of the Special Issue "Discontinuous Fiber Composites" that was published in J. Compos. Sci.

Discontinuous fiber-reinforced polymers have gained importance in the transportation industries due to their outstanding material properties, lower manufacturing costs and superior lightweight characteristics. One of the most attractive attributes of discontinuous fiber reinforced composites is the ease with which they can be manufactured in large numbers, using injection and compression molding processes. Typical processes involving discontinuous fiber reinforced thermoplastic composite materials include injection and compression molding processes as well as extrusion. Furthermore, the automotive and appliance industries also use thermosets reinforced with chopped fibers in the form of sheet molding compound and bulk molding compound, for compression and injection-compression molding processes, respectively. A big disadvantage of discontinuous fiber composites is that the configuration of the reinforcing fibers is significantly changed throughout production process, reflected in the form of fiber attrition, excessive fiber orientation, fiber jamming and fiber matrix separation. This process-induced variation of the microstructural fiber properties within the molded part introduces heterogeneity and anisotropies to the mechanical properties, which can limit the potential of discontinuous fiber reinforced composites for lightweight applications. The main aim of this Special Issue is to collect various investigations focused on the processing of discontinuous fiber reinforced composites and the effect processing has on fiber orientation, fiber length and fiber density distributions throughout the final part. Papers presenting investigations on the effect fiber configurations have on the mechanical properties of the final composite products and materials are welcome in the Special Issue. Researchers who are modeling and simulating processes involving discontinuous fiber composites as well as those performing experimental studies involving these composites are welcomed to submit papers. Authors are encouraged to present new models, constitutive laws and measuring and monitoring techniques to provide a complete framework on these groundbreaking materials and facilitate their use in different engineering applications.

Discontinuous long fiber reinforced polymer structures with local continuous fiber reinforcements represent an important class of lightweight materials with broad design possibilities and diverse technical applications, e.g. in vehicle construction. However, in contrast to continuous fiber reinforced composites, extensively used in the aircraft industry, there is still a lack of integrated and experimentally proven concepts for manufacture, modeling, and dimensioning of combinations of discontinuously and continuously reinforced polymer structures. This is partly ascribed to the complexity of the manufacturing processes of discontinuously reinforced polymers, with heterogeneous, anisotropic, and nonlinear material and structural properties, but also to the resulting bonding problem of both material types. This book addresses these issues, including both continuous and discontinuous fiber processing strategies. Specific design strategies for advanced composite reinforcement strategies are provided, with an integrated and holistic approach taken for composites material selection, product design, and mechanical properties. Characterization, simulation, technology, design, future research, and implementation directions are also included. Especially in the field of application of three-dimensional load-bearing structures, this book provides an excellent foundation for the enhancement of scientific methods and the education of engineers who need an interdisciplinary understanding of process and material techniques, as well as simulation and product development methods.

Science and Engineering of Short Fibre Reinforced Polymer Composites, Second Edition, provides the latest information on the ‘short fiber reinforced composites' (SFRP) that have found extensive applications in automobiles, business machines, durable consumer items, sporting goods and electrical industries due to their low cost, easy processing and superior mechanical properties over parent polymers. This updated edition presents new developments in this field of research and includes new chapters on electrical conductivity, structural monitoring, functional properties, self-healing, finite element method techniques, multi-scale SFRCs, and both modern computational and process engineering methods. Reviews the mechanical properties and functions of short fiber reinforced polymer composites (SFRP) Examines recent developments in the fundamental mechanisms of SFRP's Assesses major factors affecting mechanical performance, such as stress transfer and strength Includes new chapters on electrical conductivity, structural monitoring, functional properties, self-healing, finite element method techniques, multi-scale SFRCs, modern computational methods, and process engineering methods

There are many books on composite material analysis, but most cover mainly continuous fiber materials, rather than those filled with discontinuous fibers, which are particularly attractive for large-volume and low-cost applications. This book provides the theoretical and practical background to design and use discontinuous fiber reinforced polymer materials, with an emphasis on structural parts for the automotive industry. Moreover, the product of years of collaborative work between industry and academia is presented in an easy-to-use, comprehensive manner. The information provided makes it possible for someone with an engineering background to understand the micromechanics of discontinuous fiber reinforced materials and, hence, analyze the structural performance of components designed with such materials. The book employs a practical approach to cover the key, unique capabilities that are critical for a successful structural analysis of discontinuous fiber reinforced polymer structures: -Process simulation to estimate the condition of fibers in the finished parts, i.e., fiber length, orientation, and concentration -Capability to measure micro structure, i.e., fiber length distribution, fiber orientation tensors, and fiber concentration, etc. -Estimation of material properties in the part based on fiber condition, as well as environmental conditions such as temperature A broad range of areas is included, such as joining and assembly.