How to "cut" a surface inside another one?
 

Hi all,

I've been trying to do a 2d sim. Let's assume I want to model a big square, inside which I want to put another smaller square that acts as a heat generator.
If I make the sketch of a square inside a square and I extrude it, I will have a square region with a square hole in the middle. Is there a way to have the whole square surface with another square surface inside? If I do it by making two different sketches, the software automatically merges them. Any help? I don't think I have access to any other cad software, so the import/export trick is quite difficult.
If you can suggest other modelling ideas, I will hear them.

All the best

On your extrudes, set the body interaction property to none. Then do a boolean subtract of your geometries.

Thank you, I already figured that out.
Btw I think there's no need to do the boolean subtraction if the two sketches are very close (i.e. under the minimum tolerance for creating an interface).