I am using ABAQUS  to model a 3d circular crack to calculate stress intensity factor. I have already partitioned the model well and used fine mesh around the crack tip region. I used wedge type mesh around the crack tip and structured hex of other region, linear type. I set midside node parameter as 0.25, collapsed element side, single node. But the SIF output results did not converge between each contour, actually, they did not converge even for different locations of a certain contour. I can not find answers anywhere. It would be very nice if anyone could help me through this. Thanks.