When creating a new cross-section in RFEM 5 or RSTAB 8, various cross-section types are available for selection in the "Parametric - Massive" category. If you leave the mouse cursor on the button for a while, information appears that indicates in which add‑on modules you can design this cross-section (see Image 01).
The cross-sections marked in green in Image 01 can be designed with CONCRETE (for RSTAB 8) and RF‑CONCRETE Members (for RFEM 5). On the other hand, "Pi‑section, type A" is not suitable for the design with CONCRETE or RF‑CONCRETE Members. As you can see in the info, the cross-section can be analyzed with RF‑TENDON. Therefore, you can select this cross-section for a member in RFEM 5 and design it in the RF‑TENDON Design add‑on module.
Why is it not possible to design all cross-sections with CONCRETE or RF‑CONCRETE Members?
This is due to the reinforcement layers available for the individual cross-section types: For example, if you create and design a rectangular cross-section, you can find the corresponding reinforcement layers - that is, the possible reinforcement distribution - in Window 1.6 (see Image 02). Various reinforcement layouts are possible for a rectangular cross-section. These reinforcement layers are required in order to determine stresses and strains in the cross-section and thus the required reinforcement.
For other cross-sections, such as Pi‑sections, this information is not available in the current state of development. Therefore, they cannot be designed with CONCRETE or RF‑CONCRETE Members.
If the SHAPE‑MASSIVE program is licensed, you can create the structural system with a Pi‑section in RFEM 5 or RSTAB 8 and determine the governing internal forces. In SHAPE‑MASSIVE, it would then be possible to define the cross-section, to import the internal forces from RFEM 5 or RSTAB 8, and to design the cross-section according to the manual specification of longitudinal reinforcement.
Further information about SHAPE‑MASSIVE can be found by clicking the following link:
https://www.dlubal.com/en-US/products/cross-section-properties-software/shape-massive
SHAPE-MASSIVE allows you to freely define thick-walled cross-sections.
![Spans Based on Figure 5.2 from [1]](/en/webimage/039540/3493372/01_Abmessungen_EN.png?mw=512&hash=3cc425f1463bd5981b358d5889e3109e07ae1233)
