Thanks for your reply and I appreciate your help as online material is confusing and inconclusive!
I am interested in a connector that behaves such as a hardening sping. As it deflects more, rates increases. In addition, there is geometrical limitations. Maximum OD is 0.5" and minimum ID is 0.2". Force is about 70-80 lb. Relaxed length is about 0.2 " .
So, there are couple of questions:
1) Generally, What kind of connectors can provide this behavior?
2) To design a nonlinear conical compression spring, how can I define the spring parameters? Does each coil have to fit into the next coil?
3) Is there any rod shape non-linear compression spring (equal ODs at both ends) available ? e.g. made of rubber, or polymer?
Thank you in advance
Shervin