Material Science

Plastic Deformation

Shape change that remains after the force is removed

Elastic Deformation

Shape change that goes away after the force is removed (part of graph before yield point)

Stress

Axial Force divided by Cross-Sectional Area

Strain

Deformation divided by Original Length

Modulus of Elasticity

A material property that governs the relationship between stress and strain

Yield Strength

The amount of stress required to start plastic deformation;

Ultimate Tensile Strength

The highest amount of stress a material can withstand

Ductility/fracture strain

The most a material can deform before fracturing; (the last point on the graph)

(Modulus of) Resilience

The amount of energy a material can absorb before it starts plastic deformation; (area under graph before yield point)

(Modulus of) Toughness

The amount of energy a material can absorb before fracturing; (area under whole graph)

Hardness

The resistance of a material to plastic deformation