Hooke’s law is the behavioural principle of elastic materials where how the deformations are taken place in the elastic materials with respect to the applied load. Once the applied load crosses the elastic limit the material will not obey the Hooke’s law.
Hooke’s law stated that
The strain in a solid body is directly proportional to the applied stress within the elastic limit of that solid body
Application: Mechanical springs
When a load is applied on a body within the elastic limit, then the body is going to deform with respect to the load applied on it. After removing the load on the body, the body will get its original shape this happens when the body is within the elastic limit. this phenomenon can be explained with a graph between the stress and strain of the body.
The line OA on the graph shows how the stress changes with respect to the strain.
So here it is a straight line. that represents the proportionality.
This principle is used in making mechanical springs.
If the applied load is not within the elastic limit then the body will tend to permanent deformation.
The behaviour of the body with respect to the applied load shown in Stress strain curve