Cut brep to beams

I am trying to make from stresslines some beams. Unfortunately, I seem not able to cut with the cookiecutters the meshsheet.

The meshshees is thickened based on another stress-informed thickening.

Do you might know how to get beams out of this?
Do I need to cut it or is there another way of doing it you might know?

Thank you for your response. :smiley:

problem cut beams (599.1 KB)