MATERIALS REVISION BEFORE EXAMS Flashcards
(16 cards)
what is density
mass per unit volume of an object
what is hookes law
extension of a material is directly proportional to the force applied, up to the limit of proportionality
what does k tell us?
the larger the k, the stiffer the material
what do we can an increase and decrease in length
increase is extension
decrease is compression
what is limit of proportionality
point at which hookes law no longer obeyed
what is the elastic limit
the point at which a material will no longer return to its original shape
what is stress
force per unit cross sectional area
what is strain
extension per unit length
what is the UTS
maximum force per unit cross sectional area a material can withstand before it begins to neck
what is a tensile force
a force that stretches an object
what is yield stress
force per unit area at which the material extends plastically for no / a small increase in stress
what is the breaking point
the stress at this point is the breaking stress
maximum stress a material can withstand before it fractures
whats elastic region
region of graph where an object will return to its original shape when applied force is removed
whats plastic region
region on graph where an obect willl no longer return to orginual shape
permanently deformed
properties of brittle materials
- breaks with little elastic and insignificant plastic deformation
property of ductile materials
high breaking stress
it extends more before breaking
