I have tested a part in compression and obtained a stress-strain relationship that is clearly non-linear, with increasing stiffness with increasing strain. The deformation is elastic. I want to replicate this behavior in a static simulation in Abaqus, but I can't find a material model that seem to capture this behavior.

Does anyone know of a suitable material model?

I have tried:

Hyperelastic - Ended up with only the 4th order polynomial being stable for my strain range, but this still failed to converge

Porous elastic power law - Looks good on paper, but for some reason it doesn't behave as expected. If anyone has used this model before I would appriciate some help!

Plastic - This will soften the material after yield, instead of stiffening

Context: I am modeling an electrolyzer with thin plates of different materials stacked onm top of each other and loaded in compression. I want to find the pressure distribution and deformation of the layers. Since there are many layers of material, and therefore many contacts, I want the material models to be computationally efficient. Similar behavior as in the plot above is seen in multiple of the materials in the electrolyzerMaterial ModelAbaqus