I'm currently doing simulations related with contact against porous materials (Tissues) in ABAQUS. As long as I use Pore Pressure=0 as Boundary Condition everything works fine and I'm able to obtain results. The issue is that in the contact area it will be fluid flow out of the material(exudation) due to the compression imposed. The fluid flow is in both contacting zones wich violates the continuity equation.

I've worked with the FLOW subroutine in order to control the boundary conditions in the contact area, and I also have tried the *Contact permeability keyword. I even tried to impose Pore Pressure=0 as an INITIAL boundary conditions.

I have also altered the parameters used to control the solutions (As the maximum number of cutbaks) .

I've read in many places in the ABAQUS MANUAL that by default ABAQUS imposed a sealed boundary condition. I guess this might be true for free contact surfaces but in my case it the program won't run if this BC are not imposed.

Nothing of what I've tried works, the program stops without calculating the very first time increment in all previous cases. Only if I forced the Pore pressure = 0 during the whole simulation, the problem works.

Any advice?

Thanks!