Plasticity
Applied Science: BTEC Level 3 National Extended Diploma, topic 4.10.5
Plastic and Brittle Behaviour
Objects respond differently to a wide range of stresses and strains.
Plastic behaviour
- An object behaves plastically if it undergoes permanent deformation under stress.
- Plastic behaviour occurs after the elastic limit.
- Stretching strawberry laces is an example of plastic behaviour.
- To identify areas of plastic behaviour on a force-extension graph, look to the right of the elastic limit point.
Brittle behaviour
- An object is brittle if it breaks suddenly and cracks. There will be very little plastic behaviour shown.
- An example of a brittle food is hard sugar sweets.
Fractures
- Fractures happen when the material completely breaks.
Test yourself on Plasticity
Which statements about plastic behaviours are correct?
What happens when a material fractures?