Name : Redika Ardi Kusuma

Student ID : F301404 / URSEP

Composite Materials Fundamental Consideration

Composite materials can be distinguished from the other engineering materials based on

character of them and its constituent. Composite materials are composed of two or more physically

distinct phases whose combination produces aggregate properties that are different from those of

its constituents. Altought constituent materials act in concert, they are the individual materials that

make up a composite material and do not dissolve or merge into each other. Their properties can be

compared by their phase in composite (matrix or reinforcement/dispersed) and their material form

(MMC, CMC, PMC).

Parameter effects on the mechanical properties of composites materials include distribution,

concentration, orientation, shape, and size of reinforcement phase. Mechanical properties of the

composites material depend on fiber mechanical properties (critical fiber lenght) and how much load

the matrix can transmit to the fiber depending on the interfacial fiber-matrix bond. In detail, critical

fiber length depends on fiber diameter, fiber tensile strength, and fiber-matrix bond strength.

To predict various properties of a composite material made up of continuous and

unidirectional fibers, we can use a mean name Rule of mixtures. It provides a theoretical upper- and

lower-bound on properties such as elastic modulus. In this rule, upper bound modulus that

corresponds to loading parallel to the fibers may be as high as: Ec = VmEm+VpEp, whereas lower

bound modulus that corresponds to tranverse loading may be as low as: 1/Ec = Vm/Em + Vp/Ep. The

actual elastic modulus lies between the curve formed by those equation. The actual values differ

from theoritical value (rule of mixture) because particle isn’t homogeneous and there is sometimes

no perfect bounding between matrix and fibre.