Year 12 - Materials Flashcards
Breaking Stress
The tensile stress at which the material breaks.
Brittle
A material with little or no of plastic behaviour.
Density
The Mass per unit Volume.
Ductile
A material that exhibits a lot of plastic behaviour.
Elastic Behaviour
When a material will return to its original shape when the deforming forces are removed. The material will not be permanently deformed. The Elastic Limit must not be exceeded.
Elastic Energy
The energy stored in a material when it is stretched/compressed. It is equal to the work done to stretch/compress the material and can be determined from the area under a force-extension graph.
Elastic Limit
The maximum amount that a material can be extended (by a force) and still return to its original length (when the force is removed).
Extension
The difference between the loaded length and the original length.
Hooke’s Law
The extension produced (by a force) in a wire is directly proportional to the force applied.
Limit of Proportionality
The point up to which the material obeys Hooke’s Law.
Original Length
The length of the material before loading.
Plastic Behaviour
When a material will not return to its original shape when the deforming forces are removed. The material will be permanently deformed. When the Elastic Limit is exceeded.
Spring Constant
The Force per Unit of Extension.
Stiffness
A measure of how difficult it is to stretch a given material. A higher Young’s Modulus or Spring Constant increases Stiffness, as more force is needed to achieve the same extension/compression.
Tensile Strain
The ratio of extension and original length for a Material.
Tensile Stress
The force exerted percross sectional area.
Yield Point
Point at which the material extends considerably for no (or a small increase in) force or stress.
Young’s Modulus
The ratio of the stress (force per unit area) applied to a body and the resulting strain. The Gradient of a Stress-Strain Curve.
