Simulation of Belleville Spring Actuation

[jdesouza]

Does anyone have experience modeling the behavior of a belleville spring under compressive load? I would like to determine the force at which the spring actuates, or perhaps buckling is the correct term.

Should I perform a buckling analysis? I can run experiments to determine now well reality compares with theory later, but I would like to at least get started with some intelligent initial guesses via FEA if possible.

Thanks!

 

[NickE]

Cosmos is not really up to this task. I cannot tell you how I know, just that I've tried it and I was in no way able to develop a model that accurately predicts Force-Deflection curves for a bellville type of spring.

Here is why. (At least in My Humble Opinion.)

1) Large deflection solutions are not very effective in Cosmos.

2) Element Shape is not effective for the belleville type spring.

3) Too many non-linearities are present in the system.

It may be possible to get a good model using Geostar, but thats a whole different ball of wax.



Nick
I love materials science!

 

[macPT]

Maybe you should try a nonlinear analysis in Cosmos.

Regards

 

[jdesouza]

Unfortunately, we did not purchase the Non-Linear package. I don't think that would work with Cosmos NL either because of how the spring behaves;

It's pre-loaded to a certain force, then additional forces are applied until the washer snaps down, thus the force/deflection curve has multiple profiles. That's the force I'm trying to determine.

It's really not worth the time to model this when I can run a series of simple experiments and get real results, I was just hoping that I was overlooking something simple.

Thanks!

 

[NickE]

MacPT- I have the whole Cosmos Package... It just cant handle this type of analysis. Besides the Non-Linear extension of cosmos is still limited by the element shape. And the number of non-linaearities and the extreme deflection of springs make this a barely tractable problem even with really advanced softwares.

(Although you might try the old school theroy of bellvilles... I forget the guys name who came up with them. Maybe try getting hold of Associated Spring, they have a pretty good design handbook.)

 

[Heckler]

Check this link

http://www.bellevillesprings.com/

They have force-deflection curves. I would also contact them via email if you need any assistance.

I would also check with phoenix spring. They're a spring specialist. I had them make a custom spring for my needs, pricey, but you're paying for that design knowledge.

http://www.phoenix-spring.com/

Best Regards,

Heckler
Sr. Mechanical Engineer
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