# Spring Energy

Written by Jerry Ratzlaff on . Posted in Fastener

Spring energy, abbreviated as $$E_s$$, also called spring retained energy, is a measure of the potential energy stored in elastic materials as the result of their stretching or compressing.  Because of the conservation of energy, the potential energy in a spring is equal to the work required to bring it to that state.  Spring energy is based on two variables, the spring constant and the displacement of the spring. The spring constant is a material property.  The displacement is the distance the spring is compressed or stretched.

## formulas that use spring energy

 $$\large{ E = \frac{1}{2} \; k_s \; d_{s}{^2} }$$ $$\large{ E = \frac{ P \; d_s }{ 2 } }$$ $$\large{ E = \frac{ k_s \; d_s^2 }{ 2 } }$$ $$\large{ E = \frac{ \left( P\;+\; T_i \right) \; d_s }{ 2 } }$$

### Where:

$$\large{ E }$$ = spring energy

$$\large{ k_s }$$ = spring constant

$$\large{ d_s }$$ = spring displacement

$$\large{ P }$$ = spring load

$$\large{ T_i }$$ = initial spring tension