1. ### chandran

139
QUOTE:

We all know that potential energy of a spring is equal to 0.5*k*x*x were x is the displacement in the spring and k is the spring constant. This is called STRAIN ENERGY.

Only mass and elastic bodies can store energy. Why LOADING has POTENTIAL ENERGY?

Any examples?

2. ### HallsofIvy

40,664
Staff Emeritus
I think you've got it backwards! I would say that the "1/2 k x2" IS the "potential energy of loading", that the "strain energy" is the energy that deforms the spring. Assuming that the deformation is not permanent then the potential energy of the spring is the strain energy PLUS then potential energy of loading.

### Staff: Mentor

No, the "strain energy" is $1/2 k x^2$. The "potential energy of loading" is the work done by the loading force.

chandran: These concepts are used in engineering to analyze the elasticity of materials, crack formations, and lots more. You might get better answers if you asked these kind of questions in the engineering forums.

4. ### Pyrrhus

2,273
Like Doc Al explained it's basicly a concept used in engineering which came of course from the Conservation of energy. It's main use it's in solving hyperstatic structures or statically undetermined structures, it has application in the Least Work method in use with Castigliano's theorems.