Chapter 4- Testing materials Flashcards
F=
kx
Energy stored in a spring=
0.5kx2
Resisitivity equation
R=ρL/A
Youngs modlus=
How easy it is to bend, compress or stretch a thing.
Stress(σ)/Strain(ε)
Strain(ε)=
Extension/Length
Stress(σ)=
Force/Area
A material with a high strength….
requires a high stress to break
A material witha high toughness…
- Absorbs lots of energy before breaking
- undergoes lots of plasic deformation
- little crack propagation
Toughness is
the energy reqired to make new surface area, J/m2
a Brittle material
- cracks propagate easily
- little plastic deformation
- absorbs little energy before breaking
what is a hard material
one that is difficult to dent/scratch
What is ultimate tensile stress
the point where the sample is strongest
(its the highest point on a Stress v Strain graph)
breaking strength is
yield strength is
the stress required to break a material
the stress required to make a matieral yield(start doing plasic deformation)
What is a material property
What is a substance property
material-independant of the dimentions eg YM
substance- dependant on the dimentions eg extension
