RFEM provides two ways to divide surfaces:
1) Dividing Surface Equally
To split a surface equally, it has to have four sides and be convex; in other words, none of the four internal angles may be greater than 180°.
This function is available by right-clicking the surface and selecting "Split Surface". In the corresponding "Split Surface" dialog box, the number of divisions in each direction and the individual relative distances are entered.
2) Dividing Surface via Integrated Lines
If any lines are drawn within the surface plane, they may be used to divide the surface.
First, you have to check whether the division lines are integrated in the surface, which is normally the case due to the automatic object detection.
Afterwards, right-click the surface and select "Divide Surface" to use the desired function.