Spring constant/Fea

[jsteinkeATFRB]

I have rubber isolation under a platform and I would like to make/create a spring constant to this isolation so when I use the FEA, I can see how the deflection is on the platform and isolation when I add a force. How do I add a spring constant to a part and how would it reflect in the FEA?

[sthomasBEF9X]

You could create a custom material that has the proper modulus of elasticity and then the platform should deflect properly?

https://blog.federnshop.com/en/modulus-of-elasticity-in-the-spring-calculation/#:~:text=The%20modulu....

[swalton]

Rubber is a non-linear material for FEA.  The basic FEA included with Inventor Professional does not understand non-linear problems.  

A rubber spring might have large displacements under load.  The basic FEA included with Inventor Professional does not understand large displacement problems.

You will have to look at the Inventor Nastran or possibly Fusion 360 simulation packages.  There are other 3rd party FEA codes as well.  

You will also need stress-strain curves for your material and enough computer power to run non-linear, large-displacement studies.

You might find this old thread useful.

https://www.eng-tips.com/viewthread.cfm?qid=53543

[JDMather]

…also, you are doing static analysis.

If you want motion load analysis (static at time steps), you could use Environments>Dynamic Simulation and set up a Spring Force there.

I would need the Inventor file(s) to demonstrate.