[Sheyko]

Sometimes there are some shells or elements which are don't belong any parts. When I try to associate or add to part it doesn't work.
Why and how this bug to solve?

[PSYMN]

It is impossible for an element to not be in any part... please explain more...

In the mean time, I will skip the description and assume you are actually talking about hanging elements.

ICEM CFD supports many many solvers and it doesn't really know what you are planning to do with your mesh or what your mesh requirements are. That is why some of the checks are called "possible problems". Hanging elements is one of these that could be a problem or could be expected.

A hanging element is just an element with a side that is not connected to any other elements.

If you were shell meshing so you could later fill with delaunay, you would want to make sure your mesh formed a closed shape. In that case, hanging elements would mean you had a problem. You would need to close the hole or delete the tag or something like that.

But if you are shell meshing zero thickness parts or have a zero thickness baffle, you would expect to have single edges all around the edge of your shells...

I suggest that you never use the "fix" option for this error. It just deletes the shells and usually makes things worse (unless the shells are "tags" that you don't really need).

Instead, right click on the error subset and add a few layers. Do the hanging shells look like they are where they should be? Do they reveal a hole or some other problem? If there is a problem, decide what you need to do to fix it. Other wise, just move on. No worries.