modeling of Porous medium and its solution methods in ABAQUS?

Hi all,

I am krishna working on FE knee joint modeling in ABAQUS. I am beginner to Abaqus
As i have read from the journal papers, I understood that cartilage and meniscus are poroelastic (porous medium).

My axisymmetric model consists of following.
1. Cartilage is modelled with CAX4PH (axisymmetric pore pressure elements)
2. Meniscus is also with the same elements
3.Tibial bone with CAX4 elements.

Since
contact beween two deformable bodies create computational difficulties,
I am using membrane with low stiffness between the cartilage and
meniscus.

Membrane is tied to meniscus and modeled with MAX1 elements.

I got all the above information from one of the journal papers and I did the same.

But unfortunately I could not solve the problem. I need help in following aspects.

Q1:complete description of pore pressure elements?
Q2:Regarding solution methods as my model contains CAX4, MAX1 and CAX4PH elements ?
Q3:Input parameters and complete key words for pore pressure elements ?(initial condions were already given)
Q4:Physical behaviour of the porous elements ?
Q5:permeability is strain dependent, how it can be incorporated?
Q6:at
free surfaces pore pressure is zero as fluid flows freely in and out,
but what should be the boundary condition at contact of cartilage and
meniscus as there is no fluid exchange occurs across the borders ?

Any help would be greatly appreciated

Awaiting for your kind reply

Thanking you in advance !

Regards,
krishna