Energy return of elastomer

[Dan_C]

Hello,

I'm developing a product which requires a shock absorbing elastomer to compress slightly during an impact, then rebound providing energy return, similar to running shoes.
I'm just trying to figure out, does the rebound/energy return occur when
A) the force causing the compression is removed, or
B) is it related to the natural frequency of the material. I.e. the energy return occurs after a period of time determined by the frequency of the material.

Thanks in advance,
Dan

 

[GrahamBennett]

The rebound occurs when the force is remove. Please remember that not all of the original force will be released by the rubber - this is known as hysteresis.

http://www.over50sforum.com

 

[Compositepro]

Both A and B are true. The model for viscoelastic material behavior is an ideal spring with dampers in series and parallel.