Answer:
In most cases, the problem is that the finite elements of the cover surfaces are very close to each other in the edge area of the cushion when using Bézier surfaces. The FE mesh nodes of the bottom and top surfaces might be combined then. In principle, there are two approaches:
- Solving the problem numerically: You can adjust the tolerance for combining FE mesh nodes using the menu "Tools" → "Regenerate model".
- Solving the problem geometrically: A more workable solution is to increase the distance between surfaces using the boundary surfaces as shown in Image 01.
