By plotting the applied [[Stress|stress]] and resulting [[Strain|strain]] a relationship between stress and strain appears. We notice that different materials produce different stress-strain curves. For instance the curve for a [[Ductile and Brittle Behaviour|ductile]] material: ![[stress-strain-ductile.png]] Whereas the curve for a brittle material may look like: ![[stess-strain-brittle.png]]