Strain energy is the internal energy that is stored in any material which is loaded within elastic limit.
- SE is called as the work done by a loaded material.
- It is also called as ‘ Resilience’.
- Unit of SE is N-cm, N-cm, N-mm.
- For strain energy to be stored material must deform within the elastic limit.
- SE depends upon the applied load.
- When the load is removed the material will regain its original shape.
Application:- Used in springs.
The load applied on a material can be :-
- Gradually applied load.
- Suddenly applied load.
- Impact load [ load falling from height ]
Formula for strain energy:-
Strain energy (u) = ((σ)^2 × v)/2E (N-mm)
Where,
(σ) = stress in the material (N-mm^2)
E = young’s modulus
V = volume of material
Derivation of Strain Formulae:-
SE in an axially loaded member.
Stress , (σ) = P/a
Area = ½ × p × dl
= ½ × σA ×dl
= ½ × σA × (pl/AE)
= ½ × σA × (σAL/AE)
= σ^2V/2E
- The formula of SE is σ^2V/2E.
- The formula for a suddenly applied load is 2P/A
- The formula for impact loading
Authored by:- Cdt. Nikhil Choudhary, TMI
