Hi Ricardo, apologies for the delay in my reply.
Thank you for your tips. The hyperelastic coefficients were originally obtained from experimental studies looking at polymer catheters and blood vessels. I initially tried these and every sim failed, so softened the material to try and determine if this was the cause.
I have now tried moving to linear elastic definitions for both the polyer and the vessel. The vessel unfortunately, is quite soft by definition, particularly relative to the catheter. You were right about the axis of rotation.
I adjusted all the other parameters as per your suggestions including changing the BC to rotating motion.
The issue I then had was very, very small timesteps during the simulation. It took >3 core hours to achieve 1% of the sim. I then tested different max and min timesteps which resulted in failure.
Any advice would be appreciated.
Thank you!