Using XFEM with Implicit Dynamic step in Abaqus

Hi,

I have used XFEM in Abaqus for static analysis. I use traction-separation cohesive behavior with XFEM.

I want to use XFEM in implicit dynamic analysis. I am using Abaqus version 6.12. As far as I know xfem was allowed only with static analysis in earlier Abaqus versions (6.9). I read that the newer versions have implicit dynamic analysis compatiblity with XFEM.

However, when I define an implicit dynamic step, I do not see XFEM Crack Growth option in the Interactions section when I choose 'Initial Step'. Only if I select a static step, the xfem crack growth shows up in the options for initial step.

If I define a static step, define XFEM crack growth interaction and then replace the step with implicit dynamic, I get the following message in the interaction manager "XFEM crack growth is not applicable to this procedure".  I am not sure why I am not able to define XFEM crack growth in implicit dynamic analysis, any help would be really appreciated. Thanks!!

Regards,

Deepak