I am also working on soft robotics here at Rutgers University in NJ. I am following the instructions on the SoftRobotics toolkit in order to do FEA analysis using Abaqus. I am currently working with the PneuNet actuator.
Despite following all the instructions to the dot, the job ends with an error. I have spent hours and hours trying to resolve the problem but apparently for some reason the model doesn't converge mathematically.
I also noticed that if I disable inter-chamber interaction (modeling what happens when pneunet chambers swell to the point that they start touching each other, which is the big benefit of the fast actuating pneu net actuator), then the job runs and I see the deformed actuator as simulated by the software, however the adjacent chambers go through each other, so the model isn't really correct.
I hope this is useful to you if you decide to use Abaqus. I downloaded their example as well and ran it as is and still got the same errors. I even tried a different version of Abaqus. So modeling soft robots won't be easy if there is self-contact.
By the way if anyone has any info on how to get in touch with the people who put together the soft robotics toolkit, so I can ask for assistance, that would be great. Their forum isn't active. Ghost town, which is a shame. This seems like such a promising area.