Simple supported boundary condition in Comsol

Hi, guys. I'm actually studying cylindrical sound diffusers using Comsol 4.3a and I need to add simply supported boundary conditions. Is there any way to do it? I have noticed there's several conditions (displacement, acceleration, etc) and I don't know if it's possible to combine two or more to simulate a simply supported boundary condition.

Greetings from Valdivia, Chile.