ABAQUS error

Hello everyone,

I am modelling a three dimensional cohesive element problem with Abaqus. I was wondering to see if anyone had the following error in their analysis:

THE NODE NUMBERING MIGHT NOT BE CORRECT FOR ELEMENT *** INSTANCE ***

I am making my nodes with MATLAB and I am sure about the stack orientation of them. I checked the error element repeatedly and its node numbering order was correct according to Abaqus documentation. I am using zero-thickness pore pressure cohesive element to model a cylinder. When I give a thickness like 0.2, this error will go away but when the thickness is small it will come back. So if it was numbering problem, it should give me the error even when the thickness was 0.2.

I have a theory but I am not sure if it is true or not. I think since it is radial and since I generate the nodes with MATLAB (numerically) then the locations are not exact and it is possible that the nodes go into each other. That is, if the bottom node is at 8.000000001 and top node is at  8.0000000015, the middle node cannot be at 8.000000002, which in numerical calculation because of round up error this may happen. However, I thought that Abaqus has a tolerance for such a stuff which will avoid that problem specially when there is contact problem (I should use TIE to connect my CZM nodes to the body). And also if this theory is true it should work for thickness of 0.001 or 0.1 and not for 0.2 and greater.

I would be happy if someone can help me with that.

Thanks,

Navid