boundary conditions problem (Tie ,MPC ?)

Hi Every Body,

I want to lie two parts to have the same displacement when applying a pressure:

for exemple tow coaxial hoses whiche become longueur when applying a pressure (tubes).

there is :

KINEMATIC COUPLING but it works only for a déformable part with à rigid part 

i want exactly do the same as what KINEMATIC COUPLING  do but for two defromable parts.

thanks in advance