Polymer Matrix Composites (PMCs)

Types of common fabrics:

The common fabrics materials: Carbon fiber, glass fiber, Kevlar and natural fiber.

1- Woven Fabrics: Fiber Direction ( 0 – 90 )

Twill Weave:

It is recommended for carbon products that contain a lot of curvatures.

It have the same properties in the two direction x,y (Ex=Ey).

Twill Weave

Plain Weave

Biaxial Fabrics: Fiber Direction ( 45 / -45 )

2- Unidirectional Fabrics

The mechanical properties are higher in one direction (Ex dose not equal Ey)

The highest mechanical properties are in the fiber direction.

Unidirectional Carbon Fiber

Sandwich Panel Structure:

A sandwich-structured composite is a special class of composite materials that is fabricated by attaching two thin but stiff skins to a lightweight but thick core. The core material is normally low strength material, but its higher thickness provides the sandwich composite with high bending stiffness with overall low density.

Differences Between Lamina & Laminate:

• Lamina:

A lamina (also called a ply or layer) is a single flat layer of unidirectional fibers or woven fibers arranged in a matrix.

• Laminate:

A laminate is a stack of plies of composites. Each layer can be laid at various orientations and can be made up of different material systems.

• Laminate Code:

A laminate is made of a group of single layers bonded to each other. Each layer can be identified by its location in the laminate, its material, and its angle of orientation with a reference axis. Each lamina is represented by the angle of ply and separated from other plies by a slash sign. The first ply is the top ply of the laminate. Special notations are used for symmetric laminates, laminates with adjacent lamina of the same orientation or of opposite angles, and hybrid laminates. The following example illustrate the laminate code.

[0/–45/90/60/30] denotes the code for the above laminate. It consists of five plies, each of which has a different angle to the reference x-axis. A slash separates each lamina. The code also implies that each ply is made of the same material and is of the same thickness. Sometimes, [0/–45/90/60/30]T may also denote this laminate, where the subscript T stands for a total laminate.

Polymer Matrix Composites Applications in Automotive Industry:

• Car Body.

• Car Accessories.

• Car Wheel Rim: