I'm running an axisymmetric problem, and the run stopped with the error message, "Subgrid xxxxxx has small cells on axis (<radius cutoff)." Please let me know what causes this problem and how to fix this problem.
This message indicates that nodes of the specified part are on the symmetry axis so they have fallen within the limit of the radius cutoff.
If this error message came immediately after you start running your model at cycle 0, you need to check the mesh of your model to make sure the minimum side length of the smallest element is still greater than the radius cutoff.
If the error message came at the restart cycle, you need to check material status plot of the specified part. If the cells that are fallen within the radius cutoff are already failed, you need to use erosion model to erode these cells. If you already have an erosion model defined, you need to reduce the erosion strain so these cells can be eroded.
Please also check the radius cutoff value via CONTROL -> CUTOFF to see if it has a reasonable value (the default is 0.001).
Finally, calculate the average element side length in your mesh. If it is less than the radius cutoff, you need to change the length unit (for example, change it from cm to mm) to make the element side length have a bigger number.