Polypropylene/PP-foam modeling in ABAQUS.

Hi everyone.

I really need help with this one!

I currently doing my master thesis on collapse of subsea pipelines with thick coating. Normally in designing pipelines coating is neglected and I am trying to simulate whether adding the coating will have positive or negative effect on the collapse capacity of the pipeline. I have been using Abaqus for a few weeks for this task and am not experienced with it let alone modelling polymer.

Now my problem is adding the material property to the coating part. I have only been working with steel before. I have found formulas that represents stress-strain curves for PP and PP foam. How can I implement this to Abaqus? How do I approach this?