Materials Flashcards
Breaking stress
The maximum stress that an object can withstand before failure occurs.
Brittle
A brittle object will show very little strain before reaching it’s breaking stress
Density
The mass per unit volume of a material
Elastic limit
A force beyond which an object will no longer deform elastically, and instead deform plastically. Beyond the elastic limit, when deforming forces are removed, the object will no longer return to its original shape.
Elastic Strain Energy
The energy stored in an object when it is stretched. It is equal to the work done to stretch the object and can be determined from the area under a force-extension graph.
Hooke’s Law
The extension of an elastic object will be directly proportional to the force applied to it up to the limit of proportionality.
Plastic behaviour
If a material deforms with plastic behaviour, it will not return to its original shape when the deforming forces are removed. The object will be permanently deformed.
Spring constant
The constant proportionality for extension pf a spring under a force. The higher the spring constant, the greater force needed to achieve a given extension.
Tensile strain
The ratio of an object’s extension to its original length. It is a ratio of two lengths so it has no unit.
Tensile stress
The amount of force acting per unit area. Its unit is the Pascal (Pa)
Young Modulus
The ratio of stress to strain for a given material. Its unit is the Pascal (Pa)
