I'm trying to make a wing structure, created the ribs and the spars, mated them all together to get an entire internal structure of the wing. I'm trying to do some flow and bending analysis, so I added the wing sheets, made it by using the thin extrude function of the airfoil shape of thickness 0.2mm. However, when I tried to run any simulation, it keeps giving me errors about parts interfering, which is due to the ribs and the sheets. Visually, I realized there are some parts on the sheets that's protruding out between the sheets. However, both initial curves were the same, and I made sure the thin extrude was done outwards. Which means to say, the inner curve of the sheets is supposed to sit nicely on the shape of the ribs.  Does anyone have any idea how to solve this problem? Thanks in advanced