Properties Of Materials Flashcards
What is density?
A measure of mass per unit volume
What are compressive forces?
Forces that reduce an object’s size
What are tensile forces?
Forces that provide extension by pulling or stretching an object
What is Hooke’s Law?
In some objects, force and extension are directly proportional
What is spring constant?
A measure of stiffness of an object that depends on its dimensions
What is the limit of proportionality?
The point of extension where an object no longer obeys Hooke’s law
What is the elastic limit?
The point of extension where an object becomes plastically deformed
What is plastic deformation?
Where an object returns to its original shape after being stretched
What is a ductile material?
A material that will stretch a lot before breaking
What is a brittle material?
A material that will not stretch a lot before breaking
What does the gradient of a force-extension graph represent?
Spring constant
What does the area under a force-extension graph represent?
Elastic strain energy
Why is there a gap between the loading and unloading curves of rubber?
Energy is dissipated in the form of heat
What is the overall spring constant of springs in series?
1/Kt = 1/K1 + 1/K2
What is the overall spring constant of springs in parallel?
Kt = K1 + K2
What is tensile stress?
Measurement of force applied over the cross-sectional area of a material
What is tensile strain?
The ratio of extended length and original length of a material
What is the Young’s modulus?
Measure of the stiffness of an elastic material that doesn’t depend on its dimensions
What is the yield point?
The value of stress beyond which the strain increases rapidly
What is the ultimate tensile stress (UTS)?
The stress at which a material breaks
What is represented by the gradient on a stress-strain graph?
Young’s modulus
What is represented by the area under a stress-strain graph?
Strain energy per volume
What is elastic deformation?
When an object returns to its original shape after being stretched
