Is there a way to automatically cut everything away outside of an object? I'm pretty new to Blender and I'm stuck right now.

I created a complex 3D Structure with another program and imported the STL file. Now I need to "cut" this object into a cylindrical form. The object needs to be placed in a pipe after 3D printing. The boolean modifier does'nt seem to be the right option. I have tried to invert the difference operation by using a hollow cylindrical mesh but it didn't work. Does anyone have an idea how this is possible?
From what I understand (?) I would do it that way (I tried with intersect with no success)