(4.2.0) - Materials Definitions Flashcards
What is Breaking Stress?
The maximum stress that an object can withstand before failure occurs.
What characterizes a Brittle object?
A brittle object will show very little strain before reaching its breaking stress.
What is Density?
The mass per unit volume of a material.
What is Elastic Behaviour?
If a material deforms with elastic behaviour, it will return to its original shape when the deforming forces are removed.
What is the Elastic Limit?
The force beyond which an object will no longer deform elastically, and instead deform plastically.
What is 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.
What does Hooke’s Law state?
The extension of an elastic object will be directly proportional to the force applied to it up to the object’s limit of proportionality.
What is Plastic Behaviour?
If a material deforms with plastic behaviour, it will not return to its original shape when the deforming forces are removed.
What is the Principle of Moments?
For an object to be in equilibrium, the sum of the clockwise moments acting about a point must be equal to the sum of the anticlockwise moments acting about the point.
What is the Spring Constant?
The constant of proportionality for the extension of a spring under a force.
What does Stiffness measure?
A measure of how difficult it is to stretch a given object.
What is Tensile Strain?
The ratio of an object’s extension to its original length. It is a ratio of two lengths and so has no unit.
What is Tensile Stress?
The amount of force acting per unit area. Its unit is the Pascal (Pa).
What is Young Modulus?
The ratio of stress to strain for a given material. Its unit is the Pascal (Pa).
What is a fracture?
Material breaks
