ABSTRACT
This chapter considers the subject of the potential energy within a body that results from the application of external loads. Strain energy or resilience is a form of potential energy possessed by a material when strained by an external force. The work done in producing the strain is stored as strain energy. If the material is strained by a force in tension, compression, bending or torsion, within its elastic range, it will return to its unstrained state after the removal of the external force by releasing the stored strain energy. A typical example of strain energy in an elastic material resulting from a direct stress occurs, for example, when a spring is compressed or extended. The work done by applied external loads was equated to the potential energy or elastic strain energy set up within the material as a result of this external loading.
