Answer:
Yes, it is possible, but in RFEM 5 only. Unfortunately, this function does not exist in RSTAB 8.
To use the export of stiffnesses, it is necessary to activate the corresponding options in Details as shown in Image 01. Thus, the stiffnesses are exported to RFEM before the calculation and the internal forces are calculated, taking into account the rigid connections. However, no further structural model is created, but the existing model is modified.
When starting the RF‑JOINTS calculation, the eccentricity and connection are transferred to RFEM as member properties, and nodal releases are also generated in RFEM. This information can be found in the RFEM tables "1.14 Member Hinges", "1.15 Member Eccentricities", "1.24 Nodal Releases", and "1.30 Connections". The internal forces for the design checks are then determined with the modified model.
There are export options for all members for which you can define eccentricities and hinges. If there are already members with hinges or if there are trusses in the model, the additional connection hinges would lead to instabilities in the calculation. Therefore, a corresponding message appears before the dialog box is closed.
In the downloads at the end of this FAQ, you can find an example where the stiffness export is only shown for the eaves node. If you want to consider the rigidity of fasteners, you should always define all connections.
