materials key terms

Hookes law

Force directly proportional to extension up to limit of proportionality

Elastic deformation

An object returns to it’s original dimensions when deforming force is removed

Elastic limit

The maximum extent to which an object may be deformed and still return to its original dimensions when the deforming force is removed

Plastic deformation

An object does not return to its original dimensions when the deforming force is removed

Stress

Force/ cross sectional area

Strain

Extension/ origional length

Young modulus

Stress/ strain

Strong

An object can take large amounts of stress before breaking

Tough

Materials that absorb a lot of energy before it breaks

Brittle

Material does not deform or have little deformation plastically before it breaks

Ductile

Material can be drawn into wire. They have considerable plastic deformation before it breaks

Ultimate tensile stress

The maximum stress a material can withstand before it fractures

Fracture point or breaking stress

The breaking stress needed to break a material

Tension

A force that acts to stretch an object also sometimes called a tensile force