DEFINITION
Fiber-reinforced composite materials consist of fibers of high strength and
modulus embedded in or bonded to a matrix with distinct interfaces (boundaries)
between them. In this form, both fibers and matrix retain their physical
and chemical identities, yet they produce a combination of properties that cannot
be achieved with either of the constituents acting alone. In general, fibers are the
principal load-carrying members, while the surrounding matrix keeps them in the
desired location and orientation, acts as a load transfer medium between them,
and protects them from environmental damages due to elevated temperatures
and humidity, for example. Thus, even though the fibers provide reinforcement
for the matrix, the latter also serves a number of useful functions in a fiberreinforced
composite material.
The principal fibers in commercial use are various types of glass and carbon
as well as Kevlar 49. Other fibers, such as boron, silicon carbide, and aluminum
oxide, are used in limited quantities. All these fibers can be incorporated into a
matrix either in continuous lengths or in discontinuous (short) lengths. The matrix
material may be a polymer, a metal, or a ceramic. Various chemical compositions
and microstructural arrangements are possible in each matrix category.
The most common form in which fiber-reinforced composites are used in
structural applications is called a laminate, which is made by stacking a number
of thin layers of fibers and matrix and consolidating them into the desired
thickness. Fiber orientation in each layer as well as the stacking sequence of
various layers in a composite laminate can be controlled to generate a wide
range of physical and mechanical properties for the composite laminate.
In this book, we focus our attention on the mechanics, performance,
manufacturing, and design of fiber-reinforced polymers. Most of the data
presented in this book are related to continuous fiber-reinforced epoxy laminates,
although other polymeric matrices, including thermoplastic matrices, are
also considered. Metal and ceramic matrix composites are comparatively new,
but significant developments of these composites have also occurred. They are
included in a separate chapter in this book. Injection-molded or reaction
injection-molded (RIM) discontinuous fiber-reinforced polymers are not discussed;
however, some of the mechanics and design principles included in this
book are applicable to these composites as well. Another material of great
2007 by Taylor & Francis Group, LLC.
commer cial inter est is class ified as particulat e composi tes. The major con stituents
in these composi tes are parti cles of mica , silica, glass spheres , calciu m
carbonat e, and others . In general , these particles do not contrib ute to the loadcarryin
g cap acity of the material an d act more like a filler than a reinfo rceme nt
for the matr ix. Par ticulate compo sites, by thems elves , deserve a specia l atten -
tion an d are not address ed in this book.
Anothe r type of composi tes that have the potenti al of becoming an impor tant
mate rial in the future is the nano composi tes. Even though nan ocomposi tes
are in the early stage s of developm ent, they are now receiving a high de gree of
atten tion from a cademia as well as a large num ber of indust ries, includi ng
aerospac e, automot ive, and biomedi cal indust ries. The reinf orcement in nan ocomposi
tes is either nan oparticles , na nofibers, or carbon nano tubes. The effective
diameter of these reinforcements is of the order of 10
9 m, whereas the effective
diame ter of the reinf orcement s used in traditi onal fiber -reinforce d composi tes
is of the ord er of 10
6 m.
Fiber-reinforced composite materials consist of fibers of high strength and
modulus embedded in or bonded to a matrix with distinct interfaces (boundaries)
between them. In this form, both fibers and matrix retain their physical
and chemical identities, yet they produce a combination of properties that cannot
be achieved with either of the constituents acting alone. In general, fibers are the
principal load-carrying members, while the surrounding matrix keeps them in the
desired location and orientation, acts as a load transfer medium between them,
and protects them from environmental damages due to elevated temperatures
and humidity, for example. Thus, even though the fibers provide reinforcement
for the matrix, the latter also serves a number of useful functions in a fiberreinforced
composite material.
The principal fibers in commercial use are various types of glass and carbon
as well as Kevlar 49. Other fibers, such as boron, silicon carbide, and aluminum
oxide, are used in limited quantities. All these fibers can be incorporated into a
matrix either in continuous lengths or in discontinuous (short) lengths. The matrix
material may be a polymer, a metal, or a ceramic. Various chemical compositions
and microstructural arrangements are possible in each matrix category.
The most common form in which fiber-reinforced composites are used in
structural applications is called a laminate, which is made by stacking a number
of thin layers of fibers and matrix and consolidating them into the desired
thickness. Fiber orientation in each layer as well as the stacking sequence of
various layers in a composite laminate can be controlled to generate a wide
range of physical and mechanical properties for the composite laminate.
In this book, we focus our attention on the mechanics, performance,
manufacturing, and design of fiber-reinforced polymers. Most of the data
presented in this book are related to continuous fiber-reinforced epoxy laminates,
although other polymeric matrices, including thermoplastic matrices, are
also considered. Metal and ceramic matrix composites are comparatively new,
but significant developments of these composites have also occurred. They are
included in a separate chapter in this book. Injection-molded or reaction
injection-molded (RIM) discontinuous fiber-reinforced polymers are not discussed;
however, some of the mechanics and design principles included in this
book are applicable to these composites as well. Another material of great
2007 by Taylor & Francis Group, LLC.
commer cial inter est is class ified as particulat e composi tes. The major con stituents
in these composi tes are parti cles of mica , silica, glass spheres , calciu m
carbonat e, and others . In general , these particles do not contrib ute to the loadcarryin
g cap acity of the material an d act more like a filler than a reinfo rceme nt
for the matr ix. Par ticulate compo sites, by thems elves , deserve a specia l atten -
tion an d are not address ed in this book.
Anothe r type of composi tes that have the potenti al of becoming an impor tant
mate rial in the future is the nano composi tes. Even though nan ocomposi tes
are in the early stage s of developm ent, they are now receiving a high de gree of
atten tion from a cademia as well as a large num ber of indust ries, includi ng
aerospac e, automot ive, and biomedi cal indust ries. The reinf orcement in nan ocomposi
tes is either nan oparticles , na nofibers, or carbon nano tubes. The effective
diameter of these reinforcements is of the order of 10
9 m, whereas the effective
diame ter of the reinf orcement s used in traditi onal fiber -reinforce d composi tes
is of the ord er of 10
6 m.
No comments:
Post a Comment