Issue with Biphasic contact in my model

[Alexis]

Hello everybody,

I have created a knee joint model, focusing on the material properties of the meniscus and cartilage. But, when I apply biphasic contact (or any other contact (tied, sliding...)) between the meniscus and the cartilage, I always have negative jacobians. The biphasic contact between the femoral and tibial cartilage works. I would be very grateful to have some suggestions.

Thank you very much.

Alexis Hagenstein

Anglia Ruskin University

[ateshian]

Hi Alexis,

If you get negative jacobians at the very first iteration of the first time step in a contact analysis, it is possible that the contact surface normals are not pointing in the correct direction. The contacting surfaces should have normals facing opposite to each other.

Best,

Gerard