damage evolution

Hi, everybody,

I am new in modeling of damage initiation and evolution. my job is modeling damage evolution during castingrion deformation which includes two phases: matrix and graphite. Now I developed a 2D plane strain model and trie to model damage evolution. however, when I defined the damage criterion in material propertis under ABAQUS 6.10 and submitted job, the following error occurs:   

The area of  elements is zero, small, or negative. Check coordinates or node numbering, or modify the mesh seed. The elements have been identified in element set ErrElemAreaSmallNegZero.

 it should be pointted out that when damage criterion is not defined, job runs well. 

 So, could anyboday point out where the problem is? Thank you very much in advance!

Best Regards,

Hale