**STRAIN ENERGY IN GRADUAL LOAD:
**

U = Average Load x Change in length

= stress x strain x volume

Substituting the value of stress, strain, and volume of the section

The stress due to gradual load is P/A.

This is the strain energy stored in a body. – Equation (A)

**STRAIN ENERGY IN SUDDEN LOAD:**

The stress due to sudden load is found by equating the equation (A) in the following equation. (B)

U = P x δL ---- Equation (B)

Strain energy due to sudden load is found by substituting the stress ζ due to sudden load in the following equation

Strain energy due to sudden load is found by substituting the stress due to sudden load in the following equation: