Interpenetration issues in collision simulation

[3H2Oaaa]

Hi everyone：

Description

I am currently simulating the self-collision process of a cable-driven soft robot. Here is the specific setup:
The soft robot consists of multiple segments with a small initial gap (0.005mm) between them. These segments are strung together by an optical fiber and feature V-shaped notches, as shown in the image below.

When the cable is pulled, the robot begins to bend, causing the notches to close. At this point, collision occurs between the adjacent segments.
This is the scenario when the gaps close and the collision occurs.
(I’ve enabled 'Show Detection Output', and these blue dots represent the collision contact points.）
I’m curious why the collision points only appear along the outer perimeter, while the rest of the contact surface has none.

During the collision, I am experiencing severe clipping (interpenetration). Instead of rebounding or stopping at the contact surface, the segments merge and fuse into each other, as illustrated in the attached screenshot.

Additionally, I'd like to ask why the simulation crashes with 'NaN' constraint errors as soon as I set the friction coefficient (mu) to 0.1.
I have also attached my current parameter settings. Any advice on how to resolve this would be greatly appreciated!
` rootNode.addObject('CollisionPipeline', verbose=0)
rootNode.addObject('ParallelBruteForceBroadPhase')
rootNode.addObject('ParallelBVHNarrowPhase')

rootNode.addObject('LocalMinDistance', name='Proximity', alarmDistance=0.05, contactDistance=0.005)
rootNode.addObject('CollisionResponse', name='contactManager', response='FrictionContact', responseParams='mu=0.0')
rootNode.addObject('GenericConstraintSolver', name='constraintSolver', maxIterations=10000, tolerance=1e-5, computeConstraintForces=True)

collisionNode = robotNode.addChild('CollisionModel')
collisionNode.addObject('MeshSTLLoader', name='loader_coll', filename='Coll.STL')
collisionNode.addObject('MeshTopology', src='@loader_coll')
collisionNode.addObject('MechanicalObject', name='coll_dofs')

collisionNode.addObject('TriangleCollisionModel', simulated=True, moving=True, selfCollision=True)
collisionNode.addObject('LineCollisionModel', simulated=True, moving=True, selfCollision=True)
collisionNode.addObject('PointCollisionModel', simulated=True, moving=True, selfCollision=True)

collisionNode.addObject('BarycentricMapping')`

[3H2Oaaa]

Here is my python file
111.py

[3H2Oaaa]

My simulation is a self-collision scenario, meaning that the optical fiber and all its segments share a single mesh.