sliding with interference contact in LS-DYNA

[Kimpan]

I am simulating a head/helmet impact. The helmet modeled with a foam material and is fitted on the head with initial penetration. I use the contact "*CONTACT_SURFACE_TO_SURFACE_INTERFERENCE_ID".
During the impact I can see that there is no sliding between the head and the helmet regardless of what coefficiant of friction I set on static or dynamic friction.

In the contact definitions there are two curves set.

LCID1: scales the interface stiffness during dynamic relaxation

LCID2: scales the interface stiffness during transient calculation.
This is how the curves look like that I use:

 

[rstupplebeen]

The interference fit may have a default option to tie the adjusted nodes. I'm an Abaqus user so I am not sure how LS-Dyna does it. I hope this helps.

Rob Stupplebeen