Non-linear Springs

[topdraw]

Does anyone know how to force a non-linear spring to unload down a different path i.e. to generate a hysteresis effect.

 

[PamCrash]

Idea: Combine two or more nonlinear springs to get the characteristic wanted

 

[topdraw]

PamCrash. I'm not sure how this would work. Do you have any example input decks. I've been trying to use a elastic plastic beam in parallel with a spring, without much success.

 

[PamCrash]

Sorry, don't have a deck. I'd understand that you need a certain complex spring behaviour between two nodes. The idea was to superpose some nonlinear spring elements to get the desired characteristic.

 

[bkal]

I am not an ABAQUS expert, but could you use an axial (rod) element with elastic-perfectly plastic material properties. Probably not the most elegant solution, but might work.

 

[topdraw]

Thanks bkal. I have since solved the problem with exactly your suggestion and it worked a treat. I also used the cast iron material model to specify a different stress strain curve in tension and compression. A useful technique for the future.