simulate a crack propagation

[Hcham]

hi all im using abaqus 6.9 to simulate a crack propagation in an elastic material whith Xfem option, i still have this errors :the following XEFM crack are failling to correctly generate the conditions are listed whith the crack names : crack-1 Failed to locate crack tip.
and if i submit the job even the warning its abort and i get this error:the damage model has to be specified for enriched element ( nbre) instance part 1-1.i specify the damage model in Intprop as follow
** MATERIALS
**
*Material, name=Material-1
*Elastic
2.1e+11, 0.3
*DAMAGE INITIATION,CRITERION=MAXPS
8.44E7,
*DAMAGE EVOLUTION,TYPE=ENERGY,MIXED MODE BEHAVIOR=POWER LAW,POWER=1.0
4.22d4,4.22d4,4.22d4
*DAMAGE STABILIZATION
1.e-5
if any one know wat the problem whith my model tel me plz
i have 2 questions
how to specify or indicate the crack tip
how to get enriched elemnt.
tanx in advances

[Hcham]

well to simulate a crack propagation whith XEFM in abaqus .
fist thing is to create two pats ,one for the body and the second for the crack
then we assign the propriety to the body
and in the asembly module we create an assembly dependant for the crack and the body
a step specify wat u want and
in interaction module
-special >> xefm crack >> domaine and we specify the crack tip
and the most important thing is to create a constraint between the crack tip and the body
and we mesh just the body
its all