Answer:
When a beam with variable cross-section dimensions is divided retroactively, the dimensions for the beam start and beam end can no longer be modified easily. Due to the resulting intermediate nodes, a new cross-section would have to be calculated for every member segment. In order for you not to have to do this manually, we recommend deleting the members. In doing so, take care to delete only the selected members and not their nodes. The new member can subsequently be modeled from a beam start to a beam end and connected to the intermediate nodes with the "Connect Members" tool.
Summary (see Image 01):
1. Delete the members (the nodes must remain).
2. Insert a new member from the beam start to the beam end.
3. Connect the member with the intermediate nodes.
In RSTAB, the members always have to be connected to each other in a node.
This is not absolutely necessary in RFEM, because it allows a node to lie on a line without dividing the member (see Image 02). It is, therefore, sufficient to modify the cross-section at the beam start and end. If the intermediate nodes (to which the members already connect) already exist and you wish to create the tapered member retroactively in RFEM, we recommend deactivating the "Auto Connect Lines/Members" option (see Image 03). Afterwards, the member can be created without divisions at the intermediate nodes.
