Is it possible to terminate the simulation when crack starts to propagate in XFEM? How can I specify the following function? 

if (crack start to propagate)

    abaqus job=xfemjob terminate

end

Is it possible to set in input file? Or I have to resort to user subtoutine? 

Alternatively, I can control the process through shell script. But I need the abaqus output the condition variable 'crack start to propagate' to a file, so my script can assess. Question is: can I request output the stress of one nodes to a file after each incremental? 

General question: how to control the simulation process based on some variable of previous incremental? For example, stop the simulation when the displacement of one nodes is beyond a value.

Thanks a lot.

Best wishes,

Lei