This size effect is commonly analyzed by applying Weibull statistics to the strength data. The surface condition and segregation of inclusions are the two factors that limit the strength of metallic filaments. An important result of this chain alignment along the fiber axis is the marked anisotropy in the characteristics of a polymeric fiber. In service, of course, one would like the individual fibers whether in a fabric or in a composite to last a reasonable time. Service environment can be a major determining factor in the failure process of fibers. In addition, it has long been known that the excellent combination of strength and ductility exhibited by many natural fibers comes from damage tolerance imparted by their hierarchical structure. Bernholc and collaborators review the mechanical behaviour of carbon nanotubes and the role of bending in changing the electrical properties.
However, contact among the researchers working on the mechanical behaviour of natural and synthetic fibers has been very limited so far, and this book also tries to cover this gap by presenting the mechanisms and models of fiber fracture currently available for both kinds of fibers. Fractography, the study of the fracture surface, of fibers can be a useful technique for obtaining fracture parameters and for identifying the sources of failure. This book presents the mechancisms and models of fiber fracture currently available for both natural and synthetic fibers, and it is expected that increasinglythere will be cross fertilization between the fields, opening new frontiers in academic research and more competitive products for industry. In general, the mean strength of a fiber decreases as its length of diameter increases. They may be classified in two broad categories: natural and synthetic. Most of our understanding of fiber failure that appears in the chapters is borrowed from bulk concepts — such as the models based on solid state physics — and when Fracture Mechanics is used only idealized defects are considered. In fibers — and in particular in biological fibers exhibiting highly hierarchical structures — we can find differences in length scales up to five orders of magnitude; from the macromolecular level 1 nm up to macroscopic level 0.
It covers the following areas of fiber fracture: ceramic fibers; glass fibers; carbon filters;metallic fibers and thin wires; polymeric fibers; and carbon nanotubes. High-strength organic fibers fail in compression at strains 1500°C. This makes it difficult to sort out the main structures responsible for the mechanical response one is looking for and this task is more involved when dealing with imperfections. In this paper, examples of fracture in different types of fibers are provided. These novel applications often require further improvements in fiber properties and research in this field is very active. Many of the books that are currently available look at different aspects of fiber processing, properties, or applications, but none are focussed on the fracture behaviour of fibers. .
They are a major component of the glass industry, which in the last two decades has seen an explosive growth due to the use of silica glass fibers as optical waveguides. Llorca review available models of fiber fracture and J. These new composite materials are rapidly taking over from the traditional structural materials metallic alloys and polymers in many industrial components, and accordingly, a new industry devoted to the manufacture of high performance fibers has emerged. Many of the books that are currently available look at different aspects of fiber processing, properties,or applications, but none are focussed on the fracture behaviour of fibers. Their fracture properties, together with critical steps in their manufacture, are reviewed by J. Hearle, stressing the relation between type of loading and fracture mode. However, they have poor properties under axial compression, torsion, and in the transverse direction.
Yoshida analyzes the influence of internal defects during the drawing of these metallic wires. One major problem in glass fibers is that of failure due to static fatigue. Bibliography Includes bibliographical references and indexes. It is expected that this effort will lead to cross fertilization between the two fields, opening new frontiers to academic research and more competitive products for industry Finally, a note on the text. Chawla presents an overview of fiber failure.
It covers the following areas of fiber fracture: ceramic fibers; glass fibers; carbon filters; metallic fibers and thin wires; polymeric fibers; and carbon nanotubes. Points of commonality and difference are highlighted. Bunsell deals with SiC fibers. Fracture in fibers, as in bulk materials, initiates at some flaw s , internal or on the surface. Both features are interwoven and deserve some comments. Such applications require high tensile strengths over long periods of time, as much as 20 years. Differences in spelling are commonplace in English books written by scholars from different countries, and they normally pass unnoticed.
Termonia summarizes Monte-Carlo lattice models for the study of the factors controlling the mechanical strength and mode of failure of flexible polymer fibers. The compressive strength of carbon fiber is intermediate to that of polymeric and ceramic fibers. It covers the following areas of fiber fracture: ceramic fibers; glass fibers; carbon filters; metallic fibers and thin wires; polymeric fibers; and carbon nanotubes. This discrepancy between the tensile and compressive properties has been the subject of investigation by a number of researchers see Chawla, 1998 for details. Their hierarchical structures are recognised as providing enhanced toughness compared to just a fine structure. Fracture is defect sensitive — contrary to elastic modulus or density — and models of fiber fracture should take into account — and model — such imperfections. Oxidation treatments tend to remove the surface defects and thus increase the strength levels of the.
In order to get high strength and stiffness in organic fibers, one must obtain oriented molecular chains with full extension. This behavior is shown by organic fibers such as cotton, aramid, as well as inorganic fibers such as tungsten, silicon carbide, glass, or alumina. The last section is devoted to fracture of nanotubes. This is not the case, however, in this book where they appear in the very title. The fiber elastic modulus, however, is unaffected because the elastic strains involved in the modulus measurement are too small. The fifth block is devoted to metallic fibers and thin wires, relevant in the tyre industry, in electrical and electronic applications as well as in civil engineering.
The second block is devoted to ceramic fibers, relevant to high temperature metal and ceramic composites. In general, because of the high surface to volume ratio of fibers, the incidence of a surface flaw leading to fracture is greater in fibers than in bulk materials. Gupta reviews our present understanding of the strength of bare glass fibers. They are used in structural components, embedded in a matrix which maintains the fibers oriented in the optimum direction, distributes the concentrated loads, protects the fibers against wear and chemical attack from the environment, and provides the transverse stiffness to avoid buckling in compression. Llorca Free download, audio books, books to read, good books to read, cheap books, good books, online books, books online, book reviews, read books online, books to read online, online library,greatbooks to read, best books to read, top books to read Fiber Fracture by M.
Looking at the beautiful mountains, landscapes and beaches, it is hard to imagine that fracture may be triggered by defects of human size. Rigid-rod polymeric fibers such as aramid fibers show very high strength under axial tension. Many of the books that are currently available look at different aspects of fiber processing, properties, or applications, but none are focussed on the fracture behaviour of fibers. This book presents the mechancisms and models of fiber fracture currently available for both natural and synthetic fibers, and it is expected that increasingly there will be cross fertilization between the fields, opening new frontiers in academic research and more competitive products for industry. As the ductility of these links is very limited, fibers are brittle, their ultimate strength being controlled by their fracture behaviour, and further improvements in fiber properties can be obtained through a deeper knowledge of the physical mechanisms involved in fiber fracture. The main objective of A. Polymeric fibers are, perhaps, commercially the most important of all on account of the magnitude of the textile industry.