P3 - Materials Flashcards
What does p mean in the density equation?
density
What is F, k, delta L in the hooks law equation?
f = force k = the spring constant/ stiffness deltaL = the extension
What is hooks law?
extension is proportionally to the force applied up until the limit of proportionality
What is the limit of proportionality?
the point that the material follows hooks law so extension is proportional to force, beyond this point it is not
what is the elastic limit?
Once the material goes beyond the elastic limit the material will be permanently stretched, so when all the force is moved the material will be longer than before
What happens when a deformation(stretched) is elastic when the force is taken off?
If a deformation is elastic the material returns to its original shape once the forces are removed so it has no permeant extension
What happens when a deformed (stretched) material is plastic when the force is taken off?
The material will be permanently deformed
What does delta L and L mean in the tensile strain equation?
L = length
Delta L = extension
what does F, A mean in the tensile stress equation?
F = force A = cross sectional area
what does the area under a force extension graph show?
work done
What is the yield point?
The point where the material suddenly starts to stretch without any extra force
What does the area under a graph represent in a stress strain graph?
The strain energy stored per unit volume
What is a brittle material?
A material that fractures when load increase to a certain point because it has a low level of tensile stress
What is youngs modullus?
How stiff a material is
Stress/ strain
what does the gradient of a stress strain graph give?
What does the area under the graph give?
youngs modullus
Energy per unit volume
