Help with increasing the convergence of a Fiber Reinforced Soft Actuator Model

[tolstoys19]

Dear SOFA Community,

I have also uploaded this discussion to the Defrost Soft Robots team forum:

SofaDefrost/SoftRobots#212

I am working on developing on a model of a small fiber reinforced soft actuator. For modeling the fiber reinforcement I am basing myself on this paper:

https://ieeexplore.ieee.org/abstract/document/9981637

I am using the stiffspringforcefield to model the fibers. The idea of the fibers is to limit radial expansion and also to assist with bending, all the loops are interconnected at the bottom section of the actuator(see BottomSection.jpeg).

I am currently having the problem that for high air pressures the actuator looks like it explodes(see image ChamberProblem.jpg on the uploaded files) and stops converging. Do you have any ideas as to why this could be happening and any way to fix it? I have trying refining the mesh between coarser and finer sizes but it doesn't seem to help.

I have attached my files in here: The simulation is called measurements_working.py
QuestionConvergence.zip

PD: Also, I would be grateful if you by any chance had any feedback regarding the way I am modeling the fiber reinforcement.

Thank you for your time.