Facet joint contact

Altair Forum User

Hi, 

 

 

I have a methodological question. I try to create the facet joint contact of two vertebrae in radioss. I have the bone model as stl file imported, and know that a very small cartilage layer (0.2mm) coats the surface of the bone at the location of contact on both sides. Friction is negligible. 

--> see images: , ! (red and yellow surface are the cartilage layers)

My idea was to create a shell layer with 0.2mm offset from the surface and connect it to the solid bone using a type 2 contact with elastic behaviour (penalty formulation). I do this on bodes sides and define a type 7 contact between the two shell layers. Is this the correct approach? What parameter (especially for the type 7 contact) are important and how to set them correctly? 

 

Thanks in advance! 

Unable to find an attachment - read this blog

Altair Forum User

Hi,

This model setup seems to be fine and try running the same.

The suggested parameters for TYPE7 contact are:

Istf=4

Igap=2

Fscale_Gap=0.8

INACTI=6

Gap_min=0.1

Fric = 0.1

Iform=2

Altair Forum User

Ok, I will try that and give you response. Thanks!