Spring Back Force

Discussion created by 1-F6SDEU on Apr 22, 2009
I am analyzing a plastic basket spring (imagine an inverted basket). The rim of the basket spring is constrained and force (unknown) is acting on top surface. I know the displacement of of the spring as the travel of the plunger that is pushing the top surface is constant. The plunger pushes the spring down to 0.18 inches and retracts. I want to know what is the force that this plastic spring puts back on the plunger as the plunger retracts. How do I set up this problem?

{Here is what I have done so far:
A) Define Stress-Strain Curve for Plastic material.
B) Define Displacement constraint (use reference geometry) for the top surface and use loading-unloading curve (to simulate plunger down-&-up)
C) Run a Non-linear Static Analysis}