Page 10 - Fiber Fracture

PREFACE

Fibers stand among the stiffest and strongest materials either present in nature or
manufactured by man. 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. 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. The world wide production
of high performance fibers was in excess of 2 millions tons in the year 2000, and it’s
growing rapidly as new potential uses are envisaged every day.
These novel applications often require further improvements in fiber properties and
research in this field is very active. As a result, numerous books and conference
proceedings are available on different aspects of fiber processing, properties, or
applications but none is focused on the fructure behaviour of fibers. Man-made high
performance fibers derive their outstanding properties from the strong ionic, covalent or
metallic bonds which sustain the load. 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 bc obtaincd through a deeper knowledge of
the physical mechanisms involved in fiber fracture. 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. 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. 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. Differences in spelling are commonplace in English books
written by scholars from different countries, and they normally pass unnoticed. This
is not the case, however, in this book where they appear in the very title. Fiber (the
american way) and fibre (the traditional British form) are both used freely throughout
the book and, although aesthetic considerations would recommend the choice of one or
the other, we have decided to keep the original spelling used by each author.