Answer:
The "Rib" member type is suitable primarily for reinforced concrete elements, as the contribution of the slab is usually taken into account in the design. When defining the "Rib" member type, the internal forces are integrated in the program due to the slab contribution.
If you decide on the "Rib" member type, pay attention to the activation/deactivation of the effective contribution on the surface; see Project Navigator - "Display", "Results".
If internal forces are only required for the member without considering the slab contribution, select the "Eccentric Beam" member type.
For a design using an add-on module, the same results are obtained for the "Rib" member type as for the eccentric beam.
