ABAQUS - Problem concerning "concrete damaged plasticity" model

Hi all,

I'm trying to solve a frame structure in ABAQUS. I'm using 3D beam elements (B31) so that shear and bending stresses may appear. This is ok for an elastic analysis, but I also want to perform a failure analysis of this frame. Therefore, I'm trying to use the "concrete damaged plasticity" material in ABAQUS.  But I've read in the manual I can't use B31 elements with this material.

 Does anyone know how to combine the "concrete damaged plasticity" material in a 3D beam analysis? Any other suggestions?

 I tried "brittle cracking" so far and it didn't work either. I also tried both with truss elements and it worked, but I need to model shear and bending behavior as well.

 Thanks in advance,

Paco.