Composites And Non-metallic Structures Flashcards
What is a composite?
When two or more materials combine to form a stronger structure
What are some advantages of composites?
High strength to weight ratio
Reduction of parts and fasteners
Reduction of wear
Corrosion resistance
What are some disadvantages of composites?
Relatively expensive
Not easy to repair
Trained staff and equipment required
What does reinforcing materials do?
It gives major strength to the reinforcing component when combined with a matrix
Name a type of composite
Nomex
Name some properties of nomex?
It is manufactured only as a fibre
It has high thermal stability
It is flame resistant
How is fibre glass made?
It is manufactured from molten silica glass and spun together then woven into a cloth
Name one advantage and disadvantage of fibre glass
Advantage - low cost
Disadvantage - weighs more than other fibres
The simplest composite is made of two elements. What are they?
The matrix - adhesives or resins
The reinforcing material - fabric
What are the two types of fibreglass most commonly used in the aerospace sector?
E Glass (highly resistant to electricity) S Glass (very high tensile strength)
What are some characteristics of Aramid fibres?
Yellow in colour High strength to weight ratio High Tensile strength Heat resistant up to 260C Low density Abrasion resistant Chemical resistant Non flammable and non fusible High toughness
What is Kevlar?
A man made organic fibre with high tensile strength and flexibility
What is Kevlar used for?
Bullet proof vests, cables and reinforced composites for aircraft panels
How does Kevlar work?
NOT COMPLETED
What are some disadvantages of Kevlar
Difficult to cut
Absorbs up to 8% of moisture
What are some characteristics of Carbon Fibre?
High E modulus High strength Low density Low fracture resistance Thermal extension in longitudinal direction in the fibre close to 0 High resistance against temp Electrically conductive
What does CFRP stand for?
Carbon Fibre Reinforced Plastic
What are the different Fibre Orientations?
Warp
Weft/fill
Selvage edge
Bias
Uni directional Fibre
Bi directional Fibre
What is Warp?
The threads that run along the edge of the fabric
What is the weft/fill?
The fibres that run perpendicular to the warp fibres
What is the Selvage Edge?
The tightly woven edge that runs perpendicularly to the warp edges
Wha is the Selvage Edge used for?
Used to prevent unravelling edges
What is the Bias?
The thread that runs 45 degrees to the warp threads
What does the Bias do?
It allows manipulation of the material to create complex contours